the Air abroad were much heated at that time of the year which was in that season or at least very near it that is wont to be call'd the Dogg-Daies CHAP. IIII. ANd as we have shewn that the Subterraneal Air even in the first Region is usually much less heated then the Superterrestriall Air so we may also easily observe that That Inferior Air is Caeteris paribus wont to be much less refrigerated by the grand Efficients of intense Cold then the Superior Air. I will not urge on this occasion what I have observed by a surer way then for ought I know has been before practised about the smoaking of some Springs in Frosty Weather because I doe not know but that those Springs may have come from or passed a good way through some place very deep beneath the Surface of the directly incumbent ground and perhaps from a Soil peculiarly fitted to warm them whence the water may have deriv'd a warmth considerable enough not to be quite lost till it began to spring out of the ground where it needed only not to be quite Cold to appear to smoke the intense Coldness of the Air making those exhalations visible in Frosty Weather which would not be so in milder As is evident in a mans Breath which appears like a smoak in such weather though it be not visible in Summer That therefore which I shall propose in favour of our observation is first taken from the nature of the thing which may perswade us that the Subterraneall Air being though comparatively cool yet indeed moderately warm in Summer ought not to be affected with Winters Cold so much as that contiguous to the Surface of the Earth from whose immediate Contact it is by a thick arch of Earth if I may so call it defended and that the Cold reigns most in the free Air and the Superficiall parts of the Terrestriall Globe may appear by Waters beginning to freeze at the Top not at the Bottom To which Reason from the nature of the thing I shall add only this from experience that we see that in Cellars that are arch'd and carefully kept close from the Communication of the outward Air Beer and other Liquors may be kept from freezing in frosty and snowy Weather As I have observed in a cellar that was but shallow but well arch'd in a Winter that was sharp to a wonder and froze stronger Liquors then Beer in another Cellar very near it that differed not much from it in depth but had not so thick and solid a roof And that not only here in England where the Cold is less violent but even in Russia it selfe where it is wont to be so extream it reaches not near so deep as one would think I learn'd by Inquiry purposely made of an ingenious Physitian that lived at Mosco who answered me that others and he himselfe did in that City keep all the Winter long not only their Wine but their Beer from freezing in Cellars that were not above 12 or 14 foot deep but well cover'd above and carefully Lin'd with plankes of Firr without any entrance but a small trap-Door commonly at the top which was fitted so exactly to the Orifice it was to close as to exclude as much as was possible all communication between the internall and externall Air that the latter might not affect the former with it's Coldnesse I have indeed suspected that in some Cellars the comparative warmth we find there may be partly due to Subterraneall Exhalations that are pent up in them and perhaps too in some measure from the Steams of the fermenting or fermented Liquors lodg'd in those places And I was somewhat confirmed in this Suspition by an Information my Inquiries obtained from the newly mentioned Doctor who told me upon his own observation that in one of the Cellars he made use of at Mosco having occasion to open the above mentioned trap-door after the Cellar had for a good while been kept very close shut there came out at the vent that was thereby given a copious Steam in the forme of smoak which to them who had their Bodies affected with the externall Air was very sensibly warm and was almost unfit for Respiration Which Circumstance increased my suspition that there might be among these steames some of the nature of those that have been observed to come from fermenting Liquors especially Wine and so abound in some Cellars as almost to stiffle those that ventured into those Vaults And to kill some of them outright Which effects the long abode of Subterraneall Steams in stagnating Air even in many places where no metalline Oars at all not other noxious mineralls have been found has enabled that Air to produce Of which divers sad Instances have been given within lesse then a mile of this place upon mens first going down into pitts or Wells that had not in a long time been open'd or made use of but this is here mentioned only upon the By nor have we any necessity to fly to Subterraneall Exhalations for the Comparative warmth that good Cellars in generall afford in frosty weather since that Phaenomenon may be accounted for by the reason formerly given That the closenesse of the Cavity and the thicknesse of the sides and Roofe keep it from being vehemently affected with the Cold of the Ambient Air. I know 't is pretended that the warmth we speak of proceeds from an Antiperistasis but not now to engage in a controversy that would take up too much time it may here suffice to represent that in our case there appears no necessity of recurring to it the Phaenomenon being solvable by the Region newly cited which may be confirmed by this Experiment that in the Vaulted Cellar above mention'd wherein Beer was kept from freezing in an almost prodigiously sharp Winter the included Air though sensibly warm to those that came out of the free Air had not so intended its native heat as the Assertors of Anâ—iperistasis would have expected being Colder then the free Air commonly is in that place not only in the heat of Summer but in other seasons when the weather is Temperate As I was assur'd by comparing my own observations made at other times with the account brought me by a skillfull person whom I employ'd into that Cellar at late hours in one or two of the sharpest nights of the forementioned cruell winter with the same excellent seal'd weather-glass that I had long kept suspended within a stones cast of that place CHAP. V. HAving said thus much about the Earths uppermost Region I now proceed to that which lies next beneath it whose Temperature I cannot so conveniently give an account of in less then two Propositions whereof the First is this Proposition the first The Second Region of the Earth seems to be for the most part cold in comparison of the other two This proposition may be confirmed partly by Reason and partly by experience And first it seems consonant to Reason that since
effect The Relation here meant is afforded us by the following Passage taken out of the Voyage of Monsieur de Monts into New-France whereof he went to be Governor where the Relator thus recites his observation About the eighteenth day of June we found the Sea-water during three dayes space very warm and by the same warmth our wine also was warme in the bottom of our ship yet the Air was no hotter then before And the 21 of the said moneth quite contrary we were 2 or 3 days so much compassed with mists and cold that we thought our selves to be in the moneth of January and the water of the Sea was extreame cold which continued with us untill we came upon the Bank by reason of the said mists which outwardly did procure this cold unto us This effect he attributes to a kind of Antiperistasis in the following part of his narrative which I shal not now either transcribe or examine CHAP. 3 And thus much being breifely noted touching the upper Region of the Sea and the requisite Cautions that may perhaps extend further then it being premised it remains that I take notice of the Temperature of the Lower Region which in one word is Cold unlesse in some few places to be presently mentioned For water being in it's naturall or most ordinary state a liquor whose parts are more slowly agitated then those of mens Organs of Feeling must be upon that account Cold as to sense and consequently it need not be strange that those parts of the Sea which are too remote to be sensibly agitated by the Sun-Beams or wrought upon by the warmth which the Air and upper parts of the Earth may from other Causes receive should be felt Cold by those that descend into it unlesse in those few places where the Coldnesse may be either expell'd or allay'd by hot Springs or Subterrestriall Exhalations flowing or ascending from the subjacent Earth or the lower parts of the shore into the incumbent or adjacent parts of the water To justifie my ascribing of this Coldnesse to the second or lower Region of the Sea I shall now subjoin some Relations I procur'd from persons that had occasion to goe down into it or otherwaies take notice of its Temperature in very differing Regions of the World and at very unequall depths And first as to the Temperature of the lower Region in the Northerne Sea I had the opportunity to converse often and sometimes to oblige a man bold and curious enough who for some years got the best part of his subsistence by descending to the bottom of the Sea in an Engin whose structure I elsewhere describe to seek for and recover Goods lost in Shipwrackt Vessels This person I diligently examined about divers Submarine Phaenomena about which his answers may be elsewhere met with And as to the Temperature of the lower parts of the Sea the knowledge of which is that alone that concerns us in this place he severall times complained to me of the Coldnesse of the deep water which kept him from being able to stay in it so long as he might have been put into a condition of doing by the goodnesse of his Engin for I remember that he related to me that he staid once betwixt an hour or two at a depth that was no greater then 14 foot and a half upon the coast of Sweden in a place that was near the shore and I afterwards learnd that he staid much longer in a deeper place use having probably made the Cold more supportable to him He told me then that about two years before he was engaged by a good reward to goe down with his Engin to the bottom of the Sea to fetch up some Goods of value out of a Ship that had been cast away there within about a miles distance from a very little Island and if I mistake not about 6 miles from the Shore He farther answered me that though he felt it not at all Cold on the Surface of the Water his attempt being made in June yet about the depth of the Ship it was so very Cold that he felt it not so Cold in England Winter and Frosty VVeather And he told me that an excessive Cold was there felt not only by him but by very sturdy men who invited by his example would needs also goe down themselves to participate and promote the hoped for Discovery He told me also that the upper water did but cool and refresh him but the deeper he went the Colder he felt it which is the more considerable because he had some times occasion to stay at 10 fathoms or even 80 foot under water And I since found that he informed divers Virtuosi that purposely consulted him that he found the Coldnesse of the Water encrease with its depth and gave that for the reason why he could not stay so many hours as otherwise he might at the bottom of the Sea Adding that before his Engin was well fitted he was once so covered over with it that he was forced to touch the ground with his hands and feet and the neighbouring parts to which he found a Coldnesse communicated by the Fundus he lean'd upon though the closenesse of his disordered Engin made the other and whilst he was in that posture upper parts of his Body of a very differing Temper An inquisitive person of my acquaintance that made a long stay in the Northerne America at about two or three and forty degrees of Latitude and diverted himselfe often with swimming under water answered me that though he scarce remembred himselfe to have dived above two fathoms beneath the surface of the Sea yet even at that small depth he observed the water to increase in coldnesse the lower he descended into it Which argues that though the Sun-Beams do often penetrate plentifully enough to carry light to a great depth under water yet they doe not alwaies carry with them a sensible heat and that at least in some places the upper Region of the Sea reaches but a little way The coldnesse of the Climate in these western parts of Europe and the want of considerable inducements to invite men to dive often to any great depth into our Seas has kept me from being able to procure many observations about the temperature of their lower Region but upon the hotter Coasts of Africk and the East-Indies the frequent Invitations men have to dive for Corall pearles and other Submarine Productions has made it possible for me to get more numerous observations some of which I shall now annex CHAP. 4. MEeting with a Person of Quality who had been present at the sishing of Corall upon the shoar of Africa and Who was himselfe practised in diving I inquired of him whether he found the Sea upon the African Coast to be much colder at a good depth then nearer the surface whereto he answered me that though he had seldome dived above three or four fathoms deep yet at that depth he found it so much
colder then nearer the Top of the water that he could not well endure the coldnesse of it And when I farther asked him whether when he was let down to the bottom of the Sea in a great diving Bell as he told me he had been he felt it very cold though the water could not come immediately to touch him he replyed that when the bell came first to the ground he found the Air in it very cold though after he had staid a while there his breath and the steams of his Body made him very hot That also at a greater depth in those hotter Climates the sea-Sea-water is sensibly Cold may be thus made probable Inquiring of a famous Sea-Commander who had been upon the Affrican Coast to what depth he was wont to sinck his Bottles to preserve his Wine any thing coole in that excessive hot Climate he Answered me that in the day time he kept it in a tolerable temper so as to be drinkable by keeping it in the Bottom of the ship and in sand but in the morning he had it coole enough by sincking his Bottles over night into the Sea and letting them hang all night at 20 or 30 fathom deepe under water Inquiring also of an intelligent Gentleman that was imploy'd to the river of Gambra sayl'd up 700 miles in it in a small frigot whether he had observed that in the Sea even of those hot climats wine may be preserved coole he told me that it might and that by the means I hinted to him which was to let down when the ship came to an Anchor in the Evening severall Bottles full of wine they used that of Madera exactly stoped to ten 12 or 14 fathoms deep whence being the next morning drawn up they found the wine coole and fresh as if the vessels had been in these parts drawne up out of a well provided it were presently drink for if that Circumstance were omitted the heat of the Aire on the upper part of the water would quickly warme the Liquor I remember too that having met with a man of Letters that sail'd to the East-Indies in a Portugal-Caraet I learnt by enquiry of him that 't was the practice in that great Vessell for the Captain and other Persons of note whilst they passe through the Torrid Zone to keep their Drink whether Wine or Water cool by letting it down in bottles to the depth of 80 90 anc sometimes an hundred Fathom or better and letting it stay there a competent time after which he told me he found it to be exceeding cool and refreshing Lastly to satisfie my selfe as far as I could to how great a depth the Coldness of the Sea reached meeting an observing Traveller whose affairs or Curiosity had carried him to divers parts both of the East and VVest-Indies I enquired of him whether he had taken notice of any extraordinary deep soundings in the vaster seas To which being answered that some years agoe sailing to the East Indies in a very great ship over a place on the other side the Line that was suspected to be very deep they had the Curiosity to let down 400 Fathom of Line and found they needed no lesse Whereupon I enquired of him whether he had taken notice of the Temperature of the sounding Lead assoon as 't was drawn up To which he told me that he and some others did and that the Lead which was of the weight of about 30 or 35 l had received so intense a degree of coldnesse as was very remarkable insomuch that he thought that if it had been a masse of Ice it could not have more vehemently refrigerated his hands and when I asked in what Climate this observation was made he told me 't was in the Antarctick Hemisphere but at a great distance from the Line As indeed I concluded by some Circumstances he mentioned to me that 't was about the 35th degree of Southern Latitude CHAP. 5. These are the cheife Relations I have hitherto been able to procure about the Temperature of the Sea which if they be so confirmed by others as that we may conclude they will generally hold it wil not be irrational to conceive that in reference to Temperature those two Fluids Air and Water may have this in common that where their Surfaces are contiguous and in the neighbouring parts they happen to be sometimes cold and sometimes hot as the particles they consist of chance to be more or lesse agitated by the variously reflected Sun-Beams or more or lesse affected by â—ther causes of Heat But that part of the Air which they call the second is superior to the first as also the lower Region of the Sea being more remote from the operation of those causes doe retain their naturall or more undisturbed Temperature which as to us men is a considerable degree of coldness the Agitation of their small parts being usually in those Regions much inferior to that of the Spirits Blood other parts of our Organs of Feeling So that the Regions of the water and Air seem to answer one another but in an inverted order of situation and the Analogie might perhaps be carryed further if I had time and opportunity to doe it in this place And here I shall not dissemble that I was somewhat perplexed by meeting with a traveller that had visited the East Indian Coast near the famous Cape of Comory for asking him some questions touching the neighbouring Sea I gathered from his discourse that he concluded from that of some Divers that the Sea near Ceylom was warmer at the bottom then at the top And when I thereupon asked him whether this happened not in their Winter he replyed that it was indeed Winter though not with us yet with them it occurr'd indeed to my thoughts on this occasion that perhaps in a part of the Torrid Zone so near the Line as about 80 degrees if the Sea were not of a considerable depth the heat of the two not far distant shores of Coromandell and Ceylom might have no small influence upon the Tempetature of the water I considered also which did not a little weigh with me that in divers parts of the East-Indies and even in a Region bordering upon Coromandell where an ingenious Acquaintance of mine lived some years it has been observed that Winter and Summer are not so much discriminated by Cold weather Hot as by very Rainy weather and very dry Nay in some places the sultry heat of the Climate is more complained of in what they call their Winter then their Summer So that there will be no necessity to recur to an Antiperistasis occasioned by the coldnes of the Winter I thought too that it may perhaps be without absurdity suspected that as the bottom of the Sea in this place had a peculiar Constitution that fitted it more then others for the copious production of pearls so there might be some peculiarity in the nature of the subjacent Soil or there may be
some Subterraneali Fire or heat beneath it which may occasion an unusuall warmth in that part of the Sea by which cherishing warmth perhaps such abundance of shell Fishes teeming with pearls may be invited to settle there rather then in any of the neighbouring places But with all these conjectures I should not have been so well satisfied as with the answer I afterwards obtained by a Gentleman whose Curiosity had carried him to be an assiduous Spectator of the famous pearl-fishing near the Island of Manar between that and the Coast of Coromandell which reaches near if not fully to the Cape of Comoris For this Person having had much Conversation with the Divers for Pearls not only learn'd from them that they found the water very sensibly Cold at the bottom which in some places he estimated to be 80 or 100 fathom deep but observd divers of them at their return to the Boats to be ready to shake with Cold and hasten to the fires that were kept ready for them in little Cabines upon the shore Which Relation being accompanied with divers Circumstances of credibility and arguing the person that made it to have been acquainted with the report above mentioned and had met with some that had dived in the place whereto it had relation made me conclude that as to that report hither something extraordinary had happened in that place or that there was some mistake of him to whom 't was made or that divers did not descend to a sufficiently considerable Depth If I had been furnished with opportunity I would have engaged some ingenious Navigators to examine the Temperature of the Submarine-Regions both of differing seasons of the year especially the hottest part of Summer and Coldness of Winter with Hermetically seal'd Weatherglasses in order to the Discovery of such Particulars as these Whether there be in some Seas any such varying Differences of Temperature as may invite us at least in some places to make more then two Submarine Regions Whether the Submarine Coldnesse do at the bottom of the Sea or elsewhere either Equall or surpasse that degree which we here find sufficient to freezâ— common water Whether the parts of the Sea-water are still the Colder as they are the deeper And Whether or no this increase of Coldnesse be regular enough to be reducible to any settled proportion But for the resolving of these and the like Questions I did not causelessely intimate that a sealed Weather-glass was to be employed for I take a common one to be altogether unfit for such purposes not only because the Sea-water would mingle with such Liquors as are wont to be employed in it for that Inconveniency I could easily remedy by substituting as I have severall times don in other cases Mercury instead of ordinary Liquors but cheifely because the incumbent Sea-water would gravitate upon the restagnant Liquor of the Weatherglass and thereby render its Informations false or uncertain According to what I have had occasion to observe in another Tract Whereto that there may not in this place be any need to recur I shall add a slight experiment that I made for the satisfaction of some Ingenious men not wâ—ll acquainted with Hydrostaticks or not rightly principled in them And this Tryall I shall the rather mention because many will not allow Water to press upon Meâ—cury immersd therein tâ—â—s being a far more ponderous Liquor then that and others will expect that the included Air having no place to escape out at should resist the ascension of the subjacent Mercury more than indeed it will We made then a small Weather-glasse differing from common ones besides the bignesse in that it was turnished with Mercury instead of Water and in that we employed to contain the stagnant Mercury a Glass Viall with a narrow neck wherein by a piece of Cork or two the Stem of the Glass ball was well fastened that this globula put of the Instrument might not be lifted up when it was under water Then having by applying cold water to the outside of the Ball endeavoured to reduce the Air to the same Temper with the Water or at least to an approaching degree of Coldnesse and having taken notice of the Station of the Mercury in the shanck or stem above mentioned we did by strings tyed about the neck of the small Vial let the Instrument gently down into a large tall glas Body filled with fair water that the Liquor and Vessell being both transparent we might easily perceive the motions of the Mercury in the slender pipe By which means it appeared that as the Thermometer descended deeper and deeper into the Water the Mercury was pressed up higher and higher in the Stem And that it may not be suspected that this ascension proceeded only or cheifely from the refrigeration of the Air by the Water I shall add to what I have just now noted that though the Coldnesse of the VVater may well be supposed uniform as at least to sense yet the whole instrument being leasurely removed sometimes to the upper surface of the VVater The like Experiment we might have tryed with a Thermoscope furnished with VVater and let into Oyl or with deliquated Salt of Tartar and pure Spirit of VVine instead of Mercury and Water if we had been furnished with sufficient quantities of those Liquors and had judged it to be requisite But this Circumstance I thought fit to admonish the spectators of that t is not to be expected that the Mercury should rise as much in proportion when it is for example a foot under water as when it is but two or three Inches because according as the Instrument is let down deeper and the Air crowded into a less room the Spring of that compressed Air becomes the stronger and makes the more resistance VVhich Advertisement agreed well with the Experiment whose other Phaenomena I pas over as not pertineÌ„t to this place where I would only justifie what I said of the unfitnesse of Weather-glasses made though with other Liquors after the Common waies for making the Submarine Tryalls I proposed But till such Artificiall Observations can be obtaind we may from what has been above delivered probably gather that though the lowermost of the Submarine Regions be very sensibly Cold yet VVater at least that of the Sea does not by these Phaenomena appear to be the Summum Frigidum Though I have been severall times able to produce Ice in Saltwater yet I find not by any Observation that there has been Ice met with and generated at the bottom of the Sea under which the Earth has been found unfrozen by our Divers and appears to be soft at depths exceedingly surpassing the greatest they have reacht as is evident by the Mudd Gravell c. fetch'd from the bottom of the Sea by sounding plummets let down to 80 or 100 fathom or even a depth whereof examples may be met with in the Journalls of Navigators nâ—y my curiosity procur'd me this account from the
easily beleive him when he confesses that he felt it much the Colder because he had left of his own Clothes and put on the slight Garments used there by the Diggers He further informs his Reader that when they had descended about 80 fathoms beneath the surface of the Earth he began to feel a breath of an almost luke-warm air which warmth increased upon him as he descended lower pleasing him not a little because it freed him from the troublesome scents of his former coldnesse Adding that the Overseer of the mine who conducted him affirmed to him as also the Officers of other Hungarian mines unanimously did that in all their mines at least all the deep ones after a thick tract of Cold Earth there succeeds a Lower Region that is alwaies hot And that after they arriv'd at such a depth they felt not any more Cold but alwaies Heat how deep soever they digg And to add upon the by though this Learned Man lay much weight upon Antiperistasis yet in the next page to those that contain what I have been just now relating he either very candidly or inconsiderately takes notice that they inform'd him that their mines whether more or lesse deep they observed that at some times in the year a somewhat intenser heat was felt and the two Times that he expresly names are those oppositely qualified Seasons of Summer and Winter Having laid down these generall narratives I now proceed to consider the Earths Regions in particular about which the Summe of what I yet have to propound may be conveniently enough compriz'd in the 4 following Propositions CHAP. III. Proposition the 1. THe First Region of the Earth is very variable both as to Bounds and as to Temperature The former part of this observation will not be difficult to prove since 't will be easily granted that the manifest operation of the Sun-Beams is caeteris paribus greater and reaches further in hot Climates then in Cold ones in the midst of Summer then in the depth of Winter The Second part of the Observation may be proved by the same Arguments as the First to which may be added as to some places the Solidity or porousness of the Earth as also the nature of some Salts Marchasites and other Bodies contained in it which by their natural Temperature may dispose the Soil to Coldness or Heat As I shall have occasion to shew when I come to speak of the second Region In the mean time I have this to observe further That in this First Region the Air is usually more temperate as to Cold and Heat then that above the surface of the Earth and that this Region is not wont to be considerably deep Both parts of which Observation are capable of being made good by the same Reasons and therefore I shall endeavour to prove them jointly That in the uppermost Region of the Earth it should be less cold then above the surface seems reasonable to be allowed upon this Consideration That the Subterraneall Cavities of the Earth are sheltered by the thickness of the sides from the direct action of the Sun-Beams the Winds c. and is also kept from an immediate or at least from so full a contact of the externall Air when that is vehemently either heated or refrigerated And first as to the heat of the Sun that That does much less powerfully affect such places as are sheltered from its action by solid Bodies may appear by the Conservatories of Ice and Snow wherein frozen water is kept in that State during all the Heat of Summer and that oftentimes in Cavities that are at no considerable depth beneath the Superficies of the Earth Nay I remember that having had occasion for the perfecting of some Conclusions I was trying to keep Ice many weeks after the frosty Weather was gone and a milder Season was come in I was able to doe it contrary to the expectation of some Curious men without either digging to a notable depth in the ground or building any substantiall Structure over the Cavity For wanting conveniencies I contented my selfe though 't were in a champain place with a pit somewhat broad at the bottom of about four foot deep or lesse whose mouth was shelter'd only by a little low thatch'd hovell that was wide open to the North and only skreen'd the mouth or vent of the little pit from the direct Beams of the Sun And though I will not deny that in deep Conservatories of Snow the naturall Coldnesse of the Earth especially in some places may contribute to the effect yet I remember that discoursing once with a Traveller and Schollar that was born in hot Countries of a conjecture of mine that in an arch'd building whose walls were sufficiently thick and whose Air were carefully kept from all avoidable intercourse with the externall Air one may without digging so much as a mans depth into the Ground make a sufficient Conservatory for Ice in very open and unshelter'd places and even such as Salisbury plain it selfe discoursing as I began to say with this Traveller about this Conjecture he told me that at a place he nam'd to me in the Southern part of France whose heat seem'd to me to exceed that of divers parts of Italy some Curious persons that were resolv'd at any rate to have Ice in Summer though the Soil were such that they could not dig 4 foot without meeting with water were yet able to make use of Conservatories by covering the Brick-Building they made over their pits with Clay and Sand to a very considerable thicknesse and taking care that the only place that should permit accesse to the outward Air should be a small Northern Door to go in and out at fitted to shut exactly close and fenc'd with a little porch furnished with another Door And by this means he affirms these Gentlemen to reserve the included Ice not only all the Summer long but sometimes for two or three years together the heat of that Region making many of their Winters too mild to recruit them with Ice To all these things I shall add that even where the intercourse is not quite debarr'd but left free enough betwixt the Subterraneall and the superior Air the operation of the Sun-Beams may be very much lesse in a Cavity though but shallow beneath the Surface of the Ground then above it For besides that Tryalls have inform'd me that Liquors that differ in little else then in consistence will not so easily pervade each other as a man would surmise unlesse some externall motion hasten their intimate mingling with one another I remember that one morning pretty late having had the Curiosity to descend into a pit where they were digging out Iron Oar though this Cavity had no very narrow Orifice and was dugg directly downwards and exceeded not ten or twelve foot in depth yet I found not the heat at all troublesome whilst I staid there Though the pit were in an open feild unshaded by Trees and though
the answer I received from a very ingenious Gentleman who lives among mines and is not a little concern'd in some of them For having inquired of him What he had observed about the lying or not lying of the Snow on the minerall Soils near the place of his Residence he replyed that in some of them he did not take notice of any peculiar Indisposition to let the Ice and Snow continue on them which I conceive may proceed either from the want of such mineralls in the Subjacent parts as were then in the state of Incalescence or else from this that according to what we have elsewhere observed about the Snows on Aetna the direct ascension of the hot Steams was hindered by some Layers of Rocks or other Stone through which the Steams could not penetrate or could doe it but so slowly as to loose their actuall warmth by the way But this Gentleman added that in other places near that of his abode and such as he knew to have minerall-Veins beneath them he observed that the Snow nor the Ice would scarce continue at all upon the Surface of the Ground even in an extraordinarily cold winter It will be a considerable Instance to our purpose if it be indeed true which some learned men have written that near the Gold-mines in Hungary the leaves of the trees especially those that respct the Ground are oftentimes found ennobled with a golden-colour from the metalline Exhalations of the Gold-mines which one would think must by reason of their ponderousnesse need a considerable heat to elevate them especially into the open Air. But though doubting of this Relation as not made by mineralists or accurate Observers I inquired about it of a person whose Curiosity carried him purposely to visit those mines I was answerd that he could not be a witnesse to the truth of the Observation yet he told me an observation which I else where mention that doth not discountenance that Tradition If it be objected that what has hitherto been said about Latent Fires and heats in the Bowells of the Earth will give an account of the warmth only of those places that are within teach of the action of such Magazines of heat which probably may be wanting in many places of the Earth I shall readily confesse that as I first made this Objection to my selfe so I do not yet discern it to be unreasonable and that for ought I know if men had occasion to digg as deep and be as far conversant in many other low places of the Earth where there are no signs of Mineralls as they have done where the hopes of actuall discovery of veins of metalls and other mineralls worth working have invited them divers places in the Third Region of the Earth would be met with that would bedestitute of the warmth that has hitherto been generally found in places of the same Region that either abound with mineralls themselves or are near some of the deep and latent Aestuaries above-mentioned And as for those parts of the Third Region of the Earth which men feel not only warm but troublesomly hot that incommodious degree of heat seems not at least in some places to be derivable from the two above mentioned causes which must to produce so considerable an effect be assisted by a third cause more potent then themselves which seems to be the incalescence there is produced in many mines and other Places by the mutuall action of the component parts promoted by water of immature and more loosely contexted mineralls especially such as are of a Marchasiticall nature That such an Incalescence may by such a way be produced in the Bowells of the Earth I have elsewhere shewn in my discourse of Subterraneall Fires heats by the examples of such incalescences producible in minerall Bodies here above ground That Marchasites which for the most part abound in Vitrioll are bodies very fit to procure this Subterraneall heat may be consirm'd not only by the Sulphureous and Saline parts they abound with and by this that many of them may be wrought on as we have tryed both by simple water and even by moist Air which argues the resolublenesse of their Constitution but also by this that having purposely inquired of a Gentleman that went out of Curiosity to visit one of the deeper Hungarian mines he confirmed to me what I had otherwise been informed of by answering me that in the lower parts of the mâ—ne he had gathered Vitrioll that appâ—ared above ground to be of a golden nature and that in a Cave that is on one side of the Groove in the deep Gold-mine near Cremnitzo the corrosive smell is so strong and noxious that men have not dared to dig out the native Gold it richly abounds with being deterr'd by the ill fate of livers that ventured to work in it Adding that though he passed by it in great hast yet he could not avoid the being offended by the noysome Exhalations And on this occasion 't will not be I presume disliked if I illustrate what I was saving of Immature mineralls by subjoining That having asked this Chymist whether the Vitrioll he found very deep underground were all solid or some of it soft he affirm'd that as he gathered it he found some of it soft And to satisfy my curiosity to know whether it continued that yeilding consistence he further told me that it was soft in the deeper part of the mine but when he had brought it into the Superterrestriall Air it hardened there and appeared to have 9 divers golden streakes in it CHAP. X. ONe thing there is which must not be here omitted though it will probably be great news to those that philosophize only in their studies and have not received information from any that visited the deeper parts of the Earth The Phaenomenon is this That the Diggers in mines having found by unwelcom experience that in deep Grooves the Air unless ventilated and renewed dos in a short time become unfit for respiration have been put upon this expedient to sinke at some convenient distance from the Groove where the miners worke another pit by some called a vent pitt that usually tends directly downwards though sometimes it make Angels to which our English-minemen do in severall parts of this Kingdom give differing names whereof the most signisicant seems to be that given it in the Leadmines of Darbyshire where they call it an Air-shaft and are wont to make it 40 50 and sometimes 80 or 100 paces off and as one of the cheife and skillfull Miners there informed me as deep as the Groove or Well Though I find that the best German and some English Miners think a less depth will often suffice From this Air-shaft to the Groove the men work in there passes a Channell or if I may so call it Ventiduct to convey the Air from the former to the latter which is that that Agricola sometimes for he employs not the Terme alwaies in the same sense denotes
ignorant and shall I fear long continue so For it is to be noted with which observation I shall conclude that what has been hitherto discoursed belongs only to the Temper of those Subterraneall parts to which men have been enabled to reach by Diging 'T is true indeed that some Mines especially in Germany and Hungary are of a Stupendious depth in comparison of the generality of ours and of the more obvious Cavities of the Earth yet I find it boasted in a Discourse written purposely of the Various Mines in the VVorld that the rich Mine at Sueberg is 400 yards deep And they are scarce believed that relate one Hungarian-Mine which they visited to be 400 sathom which though double the depth of the former reaches not to half a mile But the deepest of all the mines that I have as yet read or heard of from any credible Relator is that which the experienced Agricola in the Tract he calls Bermannus Cap. 12. mentions to be at Cotteberg But this it self though it reach to above 500 fathom that is 3000 foot yet this prodigious depth dos not much exceed halfe a mile fals short of three quarters Licet variae de ambitu tervae opiniones sint nobis tamen propemodum constet esse ipsam milliarum Italiarum 26255 quod in maximo ad Terrae superficiem circulo respondeant uni gradui milliaria proximè 73. c. Gassend Instit Astronom Lib 2. Cap. 13. and how small a part is that of the whole depth of the Terrestriall Globe whose semidiameter if we admit the recent account of the Learned Gassendus reckoned at 4177. Italian miles in comparison of which as I was saying how small a thing is a depth that falls very short of a single mile FINIS Of the TEMPERATURE Of the SUBMARINE REGIONS As to HEAT and COLD OF THE TEMPERATURE Of the SUBMARINE REGIONS As to Heat and Cold. CHAP. I. THough the Aristotelians who believe water and Aire to be reciprocally transmutable doe thereby fancy an Affinity between them that I am not yet convinced of yet I readily allow of so much Affinity betwixt those two fluid Bodies as invites me after having treated of the Temperature of the Aeriall Regions to say something of that of the Submarine Regions which name of Submarine though I know it may seem Improper I therefore Scruple not to make use of because even among the Generality of Learned Men use has Authorized the name of Subterraneous Places For as these are not by this name and indeed cannot in Reason be supposed to be beneath the whole Bodie of the Earth but only the Superficiall parts of it so by the Appellation of Submarine Regions 't is not to be supposed that the places so called are below the Bottom of the Sea but only below the surface of it But to come from words to things I presume it will not be expected that I that never pretended to be a Diver should give of the Regions I am to treat of an Account build on my own Observations and I hope it may gratifie a Reasonable Curiosity about a subject of which Classick Authors are so very silent and about which Philosophers seeme not so much as to have attempted any Experiments for want of Opportunities and mean to make them I offer the best Information I could supply my selfe what by purposely conversing with Persons that have dived some without and some by the help of Engins To which I have added some reports that I judge fit to be allowed made me by Persons that had conversed with the Divers upon those Affrican and Indian-Coasts where the most famous and expert are thought to be found And I the rather report the Answers and Relationsmy Inquiries procur'd because the Informations they give us concerne a subject considerable as well as vast about which neverthelesse I among many others am not in a condition to satissie at all my Curiosity by Tryalls of my own making and because also what I shall say will probably spoile the credit of the Vulgar Error that in all deepe water of which the Sea is the Cheifest the lowermost are still the warmest parts unlesse in case that in some very hot Climates or seasons the superficiall ones happen to be a little warm'd by the Extraordinary or Violent heat of the Sun CHAP. II THough the Air and the Earth have been discriminated as to Temperature into three Regions yet the Informations I have hitherto met with invite me not to assign to the Sea any more then two The former of which may be supposed to reach from the superficies of it as far downwards as the manifest operation of the variously reflected and refracted Beames of the Sun or other Causes of warmth penetrates from which to the Bottom of the Sea the other Region may be supposed to extend According to this Division the Limits of this upper Region will not be alwaies constant for in the Torrid Zone and other hotter Climates it will Caeteris paribus be greater then in the Frigid Zone or in the Temperate Zones and so it will be in Summer then in Winter and in hot weather then in Cold supposing in these Cases the Heat to come from the Sun and Air and not as sometimes it may do from the Subterraneall Exhalations The same causes are likewise proper as 't is manifest to alter the Temperature as well as the Bounds of this Region But this Temperature may also be changed in some few places by at least two other Causes The one is the differing constitution of the Soil that composes the Shore which may affect the neighbouring water if it doe extraordinarily abound with Nitre loosely contexed marchasites or other substances capable considerably to encrease or lessen the Coldnesse of the water Another though unfrequent Cause may be the figure and situation of the lesse deep parts of the Shore which may in some sort reverberate the Heat that proceeds from the Sun and upon such an account may either add to the warmth or allay the Coldnesse that would else be found in the neighbouring water For whatever the Schools are wont to teach about the Interest of the Attrition of Air in the heat produced by the Sun Beams I have elsewhere shown by Experiments that those Beams may considerably operate upon Bodies placed quite under water Besides these two Cases that may occasion Exceptions to the generall Observation I intimated by the words at least that there might be others Because to mention now but one Example though it seem probable from what I have elsewhere delivered concerning the Subterraneall Fires and Heats that may in some places be met with even beneath the bottom of the Sea that the Phaenomenon I am going to recite may be reduc'd to the causes newly intimated yet I am not absolutly certain but that in this case whereto some others may perhaps be found resebling some other cause then those hitherto mentioned may produce or concurre to the
hard Corall Ground then suddainly deepned again from 8 to 20 and 22 fathom Sandy Ground and then suddainly saw Rocks under us where we had but 7 fathom and the next cast 14 fathom again And so having run N. N. Et. from 6 in the morning till 12 at noon about 19 mile we deepen'd our VVater from 16 to 25 and the next cast no ground with 35 fathom of Line Lastly having opportunely met with an Ancient Navigator who passes for the most experienced Pilate in our Nation for an East Indian voyage I asked him about his own Observations concerning these unequall Soundings I was answer'd that he had not only met with them elsewhere but that not far from the mouth of out Channell he had sometimes found the bottom of the Sea so abrupt that in sailing twice the Length of the ship he had found the VVater deepen from 30 fathom to a hundred if not also much more Since I received these Relations having the honour to discourse with a Noble Person who has divers times deservedly had the command of English Fleets and is no less curious then intelligent in Maritine affairs I took the opportunity to inquire of his Lordship whether he had not observ'd the bottom of the Sea to be very unequal in neighbouring places To which he reply'd that he had found it exceedingly so And to satisfy me that he spoke not upon meer cōjecture he told me that sailing once with his Fleet even in our Channell he perceived the VVater to make a rippling noise as the Sea-men call it as the Thames does under London Bridge So that he was afraid they were falling upon some shoale the VVater being 12 or 14 fathom deep and going on a little farther he cast out the Plummet again and found it about 30 fathom He added that he made divers such Observations but took notice of such rippling VVaters only when the Tide was ebbing and yet in a deep Sea meeting with the like appearance in the upper part of the water and thinking it improbable that there should be any shoale there he ordered the depth to be sounded and found it to exceed 30 fathoms and after he had passed on a very little farther he found the Sea so deep that he could not fathom it with his ordinary Line The Second SECTION ANother thing observ'd at the Bottom of the Sea is the great pressure of the water there against other Bodies For what ever men may Philosophize in their studies and may conclude from the Principles that are generally received about the Non-gravitation of Water in its proper place yet experience seems very little to favour that Generall Doctrine For first I remember that having caus'd a pretty large Cylinder of Glass that was open only at one end to be so depress'd into a large Glass vessell full of water with a conveniently applyed weight of Lead that none of the air could get out I could easily discern through the Liquor and Vessells which were all transparent that as the inverted Cylinder descended deeper and deeper the externall Water compress'd the imprison'd air and ascended higher and higher in the Cavity of the Cylinder against whose side we had before hand plac'd a row of Marks whereby to take notice of the graduall ascent and descent of the Internall Water Secondly having inquired of two severall observing Persons whereof one had with a Diving Engin visited the bottom of the Sea in a Cold Northern Region and the other had done the like in an Engin much of the same sort upon the coast of Africk I found their Relations to agree in this that the deeper they descended into the Sea the more the air they carried down with them was compassed and the higher the Water ascended above the Lip or Brim of the Engin into the Cavity of it But I shall now add a more considerable experiment or two to the same purpose For discoursing one day with an Engineer of my Acquaintance that had been often at Sea and loved to try Conclusions of a way I had thought of to make some estimate of the pressure of the water at a considerable depth beneath the surface and shew that the pressure is great there he told me he could save me the labour of some Tryalls by those he had made already and assured me that having divers times opportunity to sail near the Straights Mouth over a place where the Sea was observed to be of a notable depth he had found that if he had let down with a weight into the Sea not a strong round Glass-bottle but a Violl such as the Seamen use to carry their Brandy and strong waters in such a Vessell which might contain a Pint or a Quart of water would when it came to be sunk 40 fathom under water if not sooner be so oppress'd by the Pressure of the incumbent and laterall Water as to be thereby broken to pieces He also averred to me that having exactly closed an Aeolipille of Metall and with a competent weight sunk it to a great depth in the Sea as to forty fifty or sixty fathom deep when he pull'd it up again he found to his wonder that the great pressure of the water had in divers places crusht it inwards And though I had some suspition that the coldness of the Sea at such a depth might by weakning the spring of the included Air something contribute to the effect yet I did not admire the event having divers years before had a thin Aeolipile of Copper crusht inwards by the pressure of a much lighter Fluid then sea-Sea-water The Third SECTION ANother thing observed in the Bottom of the Sea is the Tranquillity of the VVater there if it be considerably distant from the surface For though the VVinds have power to produce vast waves in that upper part of the Sea that is expos'd to their violence yet the vehement agitation diminishes by degrees as the Parts of the Sea by being deeper and deeper lye more and more remote from the superficies of the water So that the Calm being less and less disturb'd towards the Bottom of the water if that lye considerably deep the water is there either calm or scarce sensibly disturb'd But that is for the most part to be understood of places at some distance from the shore for oftentimes in those that are too near it the progress of the waters being rudely checkt and other circumstances concurring the Commotion of the water is so great that it reaches to the very bottom as may appear by the heaps of Sand the Amber and in some places the stones that are wont to be thrown up by the Sea in and after stormes The above mentioned Calmness of the Sea at the Bottom will I doubt not appear strange to many who admiring the force of stormy Winds and the vastness of the VVaves they raise do not at the same time consider the almost incomparably greater Quantity and weight of VVater that must be mov'd to