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Word A	Word B	Word C	Word D	Occurrence	Frequency Band	MI	MI Band	Prominent
end_n	foot_n	half_a	inch_n	1,859	5	11.0254	5	true

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ID	Title	Author	Corrected Date of Publication (TCP Date of Publication)	STC	Words	Pages
A28956	A defence of the doctrine touching the spring and weight of the air propos'd by Mr. R. Boyle in his new physico-mechanical experiments, against the objections of Franciscus Linus ; wherewith the objector's funicular hypothesis is also examin'd, by the author of those experiments.	Boyle, Robert, 1627-1691.; Sharrock, Robert, 1630-1684.	1662 (1662)	Wing B3941; ESTC R26549	92,713	134

to our Examiners Funiculus since by his own confession that cannot pull up the Mercury if the Mercurial Cylinder be above 29. or 30. Inches of Mercury And therefore we shall render this reason of it That the pressure of the incumbent Air being in part taken off by its expanding it self into the Suckers dilated chest the imprison'd Air was thereby enabled to dilate it self manifestly and repel the Mercury that comprest it till there was an equality of force betwixt the strong Spring of that comprest Air on the one part and the tall Mercurial Cylinder together with the contiguous dilated Air on the other part Now if to what we have thus delivered concerning the compression of Air we adde some Observations concerning its spontaneous Expansion it will the better appear how much the Phaenomena of these Mercurial Experiments depend upon the differing measures of strength to be met with in the Airs Spring according to its various degrees of Compression and Laxity But before I enter upon this subject I shall readily acknowledge that I had not reduc'd the tryals I had made about measuring the Expansion of the Air to any certain Hypothesis when that ingenious Gentleman Mr. Richard Townely was pleased to inform me that having by the perusal of my Physico-Mechanical Experiments been satisfied that the Spring of the Air was the cause of it he had endeavoured and I wish in such attempts other ingenious men would follow his example to supply what I had omitted concerning the reducing to a precise estimate how much Air dilated of it self loses of its Elastical force according to the measures of its Dilatation He added that he had begun to set down what occurred to him to this purpose in a short Discourse whereof he afterwards did me the favour to shew me the beginning which gives me a just Curiosity to see it perfected But because I neither know nor by reason of the great distance betwixt our places of residence have at present the opportunity to enquire whether he will think fit to annex his Discourse to our Appendix or to publish it by it self or at all and because he hath not yet for ought I know met with fit Glasses to make an any-thing-accurate Table of the Decrement of the force of dilated Air our present design invites us to present the Reader with that which follows wherein I had the assistance of the same person that I took notice of in the former Chapter as having written something about Rarefaction whom I the rather make mention of on this occasion because when he first heard me speak of Mr. Townley's suppositions about the proportion wherein Air loses of its Spring by Dilatation he told me he had the year before and not long after the publication of my Pneumatical Treatise made Observations to the same purpose which he acknowledged to agree well enough with Mr. Townley's Theory And so did as their Author was pleased to tell me some Tryals made about the same time by that Noble Virtuoso and eminent Mathematician the Lord Brouncker from whose further Enquiries into this matter if his occasions will allow him to make them the Curious may well hope for something very accurate A Table of the Rarefaction of the Air. A B C D E 1 00 0 0 Subttracted from 29¾ leaves 29¾ 29¾ 1 1 2 10⅝ 19⅛ 19⅚ 2 15⅜ 14⅜ 14⅞ 3 20 2 8 9 4 8 9 15 12 4 22⅝ 7⅛ 7 7 16 5 24⅛ 5⅝ 5 19 20 6 24⅞ 4⅞ 4 23 24 7 25 4 8 4 2 8 4¼ 8 26 0 0 3 6 8 3 23 32 9 26⅜ 3 1 8 3 11 36 10 26 6 8 3 0 0 2 39 40 12 27⅛ 2⅝ 2 23 48 14 27 4 8 2 2 8 2⅛ 16 27 6 8 2 0 0 1 5● 64 18 27⅞ 1⅞ 1 47 72 20 28 ● ● 1 6 8 18 9 0 24 28 2 8 1 4 8 1 23 96 28 28⅜ 1⅜ 1 1 16 32 28 4 8 1 2 8 0 119 128 A. The number of equal spaces at the top of the Tube that contained the same parcel of Air. B. The height of the Mercurial Cylinder that together with the Spring of the included Air counterbalanced the pressure of the Atmosphere C. The pressure of the Atmosphere D. The Complement of B to C exhibiting the pressure sustained by the included Air. E. What that pressure should be according to the Hypothesis To make the Experiment of the debilitated force of expanded Air the plainer 't will not be amiss to note some particulars especially touching the manner of making the Tryal which for the reasons lately mention'd we made on a lightsome pair of stairs and with a Box also lin'd with Paper to receive the Mercury that might be spilt And in regard it would require a vast and in few places procurable quantity of Quicksilver to employ vessels of such kind as are ordinary in the Torriccllian Experiment we made use of a Glass-Tube of about six foot long for that being Hermetically sealed at one end serv'd our turn as well as if we could have made the Experiment in a Tub or Pond of seventy Inches deep Secondly We also provided a slender Glass-Pipe of about the bigness of a Swans Quill and open at both ends all along which was pasted a narrow list of Paper divided into Inches and half quarters Thirdly This slender Pipe being thrust down into the greater Tube almost fill'd with Quicksilver the Glass helpt to make it swell to the top of the Tube and the Quicksilver getting in at the lower orifice of the Pipe fill'd it up till the Mercury included in that was near about a level with the surface of the surrounding Mercury in the Tube Fourthly There being as near as we could guess little more then an Inch of the slender Pipe left above the surface of the restagnant Mercury and consequently unfill'd therewith the prominent orifice was carefully clos'd with sealing Wax melted after which the Pipe was let alone for a while that the Air dilated a little by the heat of the Wax might upon refrigeration be reduc'd to its wonted density And then we observ'd by the help of the above-mentioned list of Paper whether we had not included somewhat more or somewhat less then an Inch of Air and in either case we were fain to rectifie the error by a small hole made with an heated Pin in the Wax and afterwards clos'd up again Fifthly Having thus included a just Inch of Air we listed up the slender Pipe by degrees till the Air was dilated to an Inch an Inch and an half two Inches c. and observed in Inches and Eighths the length of the Mercurial Cylinder which at each degree of the Airs expansion was impell'd above the surface of the restagnant Mercury in the Tube Sixthly The Observations being ended we presently made the Torricellian Experiment with the above-mention'd great Tube of six foot long that we might know the height of the Mercurial Cylinder for that particular day

admit to be divisible though according to his Principles it may equalize the length of millions of his other Indivisibles nor admit a successive motion but instantaneous though that does necessarily put a body into two three ten a hundred c. places at once but will have these also to be indivisible Haste makes me pass over the absurdities about the contact of a Circle and a Line and to comprise in short all that great Explication he has given of this and other intricate as he calls them Problems which is this That the reason of the celerity of the motion of some one of these indivisibles above another is that it passes through a greater part of an indivisible in the same instant then the slower that is in plain sense no more then this One body is swifter then another because it is moved faster From whence he draws several Corollaries as that Hence may be given a reason why an Eagle is swifter then a Tortoise viz. because it moves faster I should have solved several Objections which may be brought against the divisibility of Quantity in infinitum but that as all the Scholastick Writers are full of them so it is a Subject which we are least able to dispute of having very little information of the nature of Infinity from the Senses FINIS The Citations English'd CHap. 2. Pag. 4. Cum tota vis c. Being the whole power of the Spring of the Air depends upon the Aequilibrium of its weight with twenty nine Inches and an half of Quicksilver so that this Spring doth neither more nor less in a shut place then is done by that Aequilibrium in an open place it is manifest seeing we have shewed the Aequilibrium to be plainly fictitious and imaginary that the Spring ascribed to the Air is so likewise Ibid. Nam si Tubus c. For if a Tube but twenty Inches long such as we used in our first Argument be not quite filled with Quicksilver as before but a little space be left betwixt the Mercury and the Finger on the top of the Tube in which Air onely may abide We shall find that the Finger below being removed the Finger on the top will not onely be drawn downwards as before but the Quicksilver shall descend also and that notably viz. as much as so small a parcel of Air can be extended by such a descending weight So that if instead of Air Water or any other Liquor which is not so easily extended be put in its place there will be no descent at all Hence I say against this Opinion an Argument is framed For if the external Air cannot keep up those twenty Inches of Quicksilver from descending as we have proved how shall it keep up twenty nine Inches and an half Assuredly these can no way be reconciled p. 5. Dices fortè c. You will perchance say that the Quicksilver therefore doth in the alledged case descend because it is thrust down by that parcel of Air which dilates it self by its own Spring Ibid. Sic deberet c. So should the Finger be rather thrust from the top of the Tube then thereby fastned to it because this Dilatation must be made as well upwards as downwards p. 6. Concipi c. It cannot be conceived how that Air should dilate it self or thrust down the Mercury unless by taking up a greater place which thing these Authors are much against asserting that Rarefaction can be made no other wayes then by Corpuscles or Vacuities Chap. 3. p. 7. Si c. If you take a Tube open at both ends of a good length suppose forty Inches long and fill it with Mercury and place your Finger on the top as before taking away your lower Finger you will find the Mercury to descend even to its wonted station and your Finger on the top to be strongly drawn within the Tube and to stick close unto it Whence again it is evidently concluded that the Mercury placed in its own station is not there upheld by the external Air but suspended by a certain internal Cord whose upper end being fastned to the Finger draws and fastens it after this manner into the Tube Chap. 4. p. 8 9. Sumatur c. Take a Tube shorter then twenty nine Inches and an half for instance of twenty Digits not shut as hitherto at one end but with both ends open let this Tube its Orifice being immers'd in restagnant Mercury and one Finger being plac'd underneath that the Mercury to be poured in run not through be filled with Mercury and then another Finger be applied to its Orifice to close it well Which being done if you draw away your lower Finger the upper will be found to be strongly drawn and suck'd into the Tube and so stifly to adhere to it or rather to the Quicksilver as I shall hereafter shew that it will elevate the Tube it self with all the Quicksilver and make it continue to hang pendulous in the Vessel From which Experiment this Opinion is most clearly refuted For seeing according to it the Quicksilver in such a Tube but twenty Inches long must be thrust upwards by the preponderating Air it will never by it be explained how this Finger is so drawn downwards and made so strongly to stick to the Tube For it cannot by the Air thrusting upwards be thus drawn downwards p. 11. Quod vel c. Which is thence confirmed Because if that preponderating Air succeeds as is asserted in the place of the lower Finger which was withdrawn that is if it uphold the Quicksilver after the same manner which it was upheld by the lower Finger applied under it it is manifest according to this Opinion that the Finger on the top ought not to be more drawn downwards after the lower Finger is removed then before Seeing then that Experience teacheth the contrary it is manifest that Opinion must be false Chap. 5. p. 12. Quarto c. In the fourth place it is impugn'd Because thence it would follow that Quicksilver through a like Tube might be suck'd with the same easiness out of a Vessel that Water is suck'd out of the same Which not withstanding is contrary to Experience by which we are taught that Water is easily drawn into the mouth of him that sucks whereas Quicksilver cannot be drawn thither by his utmost endeavour nay scarce unto the middle of the Tube The sequel I thus manifest Because seeing according to this Opinion that the Liquor underneath whether it be Water or Mercury may so ascend no more is requir'd but that the Air shut in the Tube may be drawn upwards by sucking which being drawn up the Liquor underneath will immediately ascend being thrust thither by the external Air now preponderating as Pecquet declares in his Anatomical Discourse p. 63. It is manifest that the Mercury may be suck'd out with the same easiness that Water is suck'd out with Which being so evidently against Experience the Opinion from whence it

inquired after and not in case it be Traction And such an Experimentum Crucis to speak with our Illustrious Verulam is afforded us by that noble Observation of Monsieur Paschall mentioned by the famous Pecquet and out of him by our Author namely that the Torricellian Experiment being made at the foot and in divers places of a very high Mountain of the altitude of five hundred fathom or three thousand foot he found that after he had ascended a hundred and fifty Fathom the Quicksilver was fallen two Inches and a quarter below its station at the Mountains foot and that at the very top of the Hill it had descended above three Inches below the same wonted station Whence it appears that the Quicksilver being carried up towards the top of the Atmosphere falls down the lower the higher the place is wherin the observation is made of which the reason is plain in our Hypothesis namely that the nearer we come to the top of the Atmosphere the shorter and lighter is the Cylinder of Air incumbent upon the restagnant Mercury and consequently the less weight of Cylindrical Mercury will that Air be able to counter-poise and keep suspended And since this notable Phaenomenon does thus clearly follow upon ours and not upon our Adversaries Hypothesis this Experiment seems to determine the Controversie betwixt them because in this case the Examiner cannot pretend as he does in the seventeenth and divers other of our Experiments that the Descent of the Quicksilver in the Tube is caus'd not by the Diminution of the external Airs pressure but from the preternatural Rarefaction or Distension of that external Air in the Receiver when by seeking to restore it self it endeavours to draw up the restagnant Mercury For in our present case there appears no such forcible Dilatation of that Air as in many of the Phaenomena of our Engine he is pleas'd to imagine It need therefore be no great wonder if his Adversaries do as he observes make a great account of this Experiment to prove that the Mercury is kept up in the Tube by the resistance of the external Aire Nor do I think his Answers to the Argument drawn from hence will keep them from thinking it cogent For to an Objection upon which he takes notice that they lay so much stress he replyes but two things which neither singly nor together will near amount to a satisfactory Answer But because that though Experiments made in very elevated places are noble ones and of great importance in the Controversies about the Air yet there are but very few of those that are qualified to make Experiments of that Nature who have the opportunity of making them upon high Mountains we did with the assistance of an ingenious man attempt a Tryal wherein we hoped to find a sensibly-differing Weight of the Atmospere in a far less height then that of an ordinary Hill But in stead of a common Tube we made use of a kind of Weather-glass that the included Air might help to make the event notable for a reason to be mentioned ere long and in stead of Quicksilver we employ'd common Water in the Pipe belonging to the Weather-glass that small changes in the Weight or resistance of the Atmosphere in opposit on of the included Air might be the more discernable The Instrument we made use of consisted only of a Glass with a broad Foot and a narrow Neck A B and a slender Glass-Pipe C D open at both ends which Pipe was so placed that the bottom of it did almost but not quite reach to the bottom of the bigger Glass A B within whose Neck A it was fastned with a close cement that both kept the Pipe in its place and hindred all communication betwixt the inward I I and outward K K Air save by the cavity of the Pipe C D Now we chose this Glass A B more then ordinarily capacious that the effect of the dilatation of the included Air I I might be the more conspicuous Then conveying a convenient quantity of Water H H into this Glass we carried it to the Leads of the lofty Abby-Church at Westminster and there blew in a little Air to raise the Water to the upper part of the Pipe that being above the Vessel A B we might more precisely mark the several stations of the Water then otherwise we could Afterward having suffered the Glass to rest a pretty while upon the Lead that the Air I I within might be reduc'd to the same state both as to coldness and as to pressure with K K that without having marked the station of the Water F we gently let down the Vessel by a long string to the foot of the Wall where one attended to receive it who having suffer'd it to rest upon the ground cry'd to us that it was subsided about an Inch below the mark F we had put whereupon having order'd him to put a mark at this second station of it E we drew up the Vessel again and suffering it to rest a while we observ'd the Water to be re-ascended to or near the first mark F which was indeed about an Inch above E the other And this we did that Evening a second time with almost a like success though two or three dayes after the wind blowing strongly upon the Leads we found not the Experiment to succeed quite so regularly as before yet the Water alwayes manifestly fell lower at the foot of the Wall then it was at the top which I see no cause to ascribe barely to the differing temperature of the Air above and below as to Heat and Cold since according to the general estimate the more elevated Region of the Air is caeteris paribus colder then that below which would rather check the greater expansion of the included Air at the top of the Leads then promote it But the better to avoid mistakes and prevent Objections we thought fit to try the Experiment within the Church and got into a Gallery of the same height with the Leads but the upper part of the Pipe being casually broken off we thought fit to order the matter so that the surface G of the remaining Water in the Pipe should be about an Inch higher then the surface of the Water in the Vessel And then my above-mentioned Correspondent letting down the Glass almost as soon as it was setled upon the pavement kneeling down to see how far it was subsided I found that not only it was fallen as low as the other Water but that the outward Air deprest it so far as whilest I was looking on to break in beneath the bottom of the Pipe and ascend through the Water in bubbles after which the Glass being drawn up again my Correspondent affirm'd that the Water was very manifestly re-ascended But because by the unlucky breaking of a Glass we were hindred to observe as we designed what would happen as well in a Weather-glass so contriv'd that the weight or pressure of the Atmosphere