the same rule the effect will be found always very near the same at least I can assure you that I have missed very often when I went to work at a venture but since I have found out ways thus to rule me I have always succeeded very well unless by some mischance Yet it is to be noted that if we would put into the pot much less meat than it can hold the pressure in this could not be made so great as in the Engine and indeed I had sometimes pots broken by the ambient water pressing upon them harder than they could bear the weight hanging from the rod LM could not give me any notice of the pressure in the pot therefore it will be better to put in too much than too little meat or if you please to do all exactly and lose nothing you may follow the directions given Chap. 2. Exper. 12. Because it would be a hard matter at Sea to make use of the contrivance described afore to know the quantity of pressure for that the motions of the Ship would shake the weights and open the valve P you must instead of that leave your Balneum Mariae empty enough that the intended heat may just make the intended inward pressure For Example if you will make ten pressures in your Engine with a degree of heat that may dry up the drop of water in 5 seconds you are to put in your Engine but ⅞ of the water it can hold and give but the said degree of heat and you may be sure that the inward pressure will be about ten times as great as the ordinary pressure of the Air as you may see Chap. 2. Exper. 16. By that means you may instead of the Iron rod and of the weight fasten the little valve P with a Screw and that will be very easie if the little pipe HH be cast with small Appendices as the Cylinder AA only things need not be strong here because the aperture is but little It will not be requisite to know all the several quantities of Water necessary to make all the several degrees of pressure with all the several degrees of heat but for ordinary use it will be enough to keep always the same quantity of water in the Engine and find by experience what degree of heat will be necessary for every operation with such a quantity of water I wish I had been able to do things as well as I have described them here then I could precisely say what quantity of coals or wood is necessary for every operation but my affairs being always uncertain I have built no Furnaces but have always set my Engine in a Chimney-corner and put the fire in the said corner between the Chimney and the Engine So it is very likely I have not kept the fire so well as might be done in a good Furnace nevertheless I will venture to give an account of several things I have already done with this Engine because that will be a good help still to find more easily the quantity of fire fit for other Engines to be made hereafter I believe also that the proportion between two several operations will be the same in all Engines I have found for Example that the quantity of coals necessary to boil Mutton is by 2 7 lesser than the quantity necessary to boil Beef So when you have found by experience what quantity is necessary to boil Beef in any Engine you must take less by 2 7 when you will boil Mutton in the same Engine and so proportionably for other Operations But before I come to give an account of the Experiments I think it will not be improper to say that after I had made the first Balneum Mariae shut by Screws I had a mind to make another shut without any Screws by the help of a great oval Valve applied inwardly but that may be taken quite out because of its oval shape which hath been described for the Wind-gun in the Honourable Mr. Boyle's Book about Physico-mechanical Experiments printed this year 1680. That Balneum Mariae is 6 inches over and 18 inches deep so that I can put in a pot that will hold 9 or 10 pounds of meat together but because the great Valve was not made strong enough to keep its figure exactly paper cannot make it tite I did always make use of leather for that purpose and because leather melts in such hot water it cannot hold long and the inward pressure drives it away and the water gets loose Nevertheless when I have met with good strong leather of an equal thickness I have been able sometimes to soften the biggest bone of a Leg of Beef without spoiling the meat but sometimes also when the leather was not good the meat was spoiled and the bones could not be softned therefore I use that Engine but seldom however if such could be made that would hold with paper alone without leather this latter way might be better than the first because the springs of the Iron hold not long so that we must look to fasten the Screws from time to time but in this latter Engine you might be sure that the greater the inward pressure is the harder would the valve be shut nevertheless I would advise you rather to shut the Balneum Mariae with Screws till the Work-men be more skilful in the making such valves Thus much for the Description of the Engine and the ways how to use it safely I shall now come to the Experiments from whence you may know some of its Proprieties and Uses but because some of the Experiments gave occasion to some Physical Observations I thought it would not be amiss to relate them though they had no connexion with the subject in hand I have therefore distinguished them by the Character that they may be left by those who care not for such things CHAP. II. Experiments for Cooks EXPERIMENT I. JVne 2. having filled my Pot with a piece of a Breast of Mutton and weighed seven ounces of Coals I lighted the fire the heat came to such a degree as to dry up a drop of water in 3 seconds time and the inward pressure was about nine times stronger than the ordinary pressure of the Air I let the fire go out of it self and the Vessels being cooled I found the remaining coal to weigh about half an ounce so that there had been but 6½ ounces consumed nevertheless the meat being taken out was found to have contracted an empyreumatical taste and the juyce of it did not turn to a Gelly so strong as when the meat is not over-done EXPERIM. II. June 4. I repeated the same Experiment and I took but 6½ ounces of coals but by blowing I made such a heat that a drop of water would evaporate in less than 2 seconds the remaining coals did not weigh full half an ounce and the inward pressure was a little greater than in the former Experiment Now although the quantity of coals had been
reckon this as a Propriety of this Engine That the more briskly we press the fire the more effect it produceth with the same quantity of coals This Experiment put me in mind to make another that might manifestly shew that the inward pressure is a great help to advance coction therefore I took two little Vessels very like one another and well fastned by Screws one of them was well soddered every where but the other had a little hole left in its cover for the vapors to get out These Vessels being filled with water and meat after the same manner and put together in the same Bath of Sand and left there in an equal heat for three quarters of an hour I took them off both together and found that the meat that had been exactly shut up was rather over than under done but the other was a great deal too raw therefore we may reckon this also amongst the Proprieties of this Engine That the greater the inward pressure is the greater effect is produced by the same heat and in the same time EXPERIM. VII Having found some difference between Beef and Mutton the one being harder to be boiled than the other I had a mind to see whether there would not be some difference also between flesh of the same kind but of different ages therefore June 4. I took Lamb and filled two Glasses with it and put some water into one of them Now since five ounces of coals have been enough to boil Mutton I took but four ounces and half for the Lamb thinking it would be more easie to be boiled I prest the fire as briskly as I could but a drop of water would not dry away in less than 11 or 12 seconds the inward pressure was eight times stronger than the ordinary pressure of the Air the heat was but so little which may be because the greater share of the coals had been once already kindled the fire being gone out by little and little I found but one dram of coals that had not been consumed In the Glass without water the bones were softned at some of the ends only but in the Glass with water the bones were all very soft yet the meat was much less savoury than in the other Vessel This Experiment caused me to think 1. That the bones of young beasts require almost as much fire as those of old ones to be boiled 2. That water is a dissolver fit to soften bones but that it impairs the taste EXPERIM. VIII Propriety That I might know pretty near what difference may be found as to the perfection of the Operation when the fire goes out of it self or when it is all taken off and quenched as soon as the heat is come to the intended degree July 5. I filled again two glass-pots with Lamb as before and having kindled a great deal of coals I prest the fire till a drop of water would dry away in 3 seconds and presently I took off all the fire I found the bones in the Pot without water a little softer than in the former Experiment and in the Pot with water I found them all very soft but the meat was not at all spoiled So I think it is near the same to press the fire with 4 ½ ounces of coals so as to dry away a drop of water in 10 seconds and then let the fire go out of it self or to press the fire with-six or seven ounces of coals and then take it all off as soon as a drop of water drys away in 3 seconds therefore the same proportion may be observed in other Operations For Example If I were to make an Operation that might be performed with a quantity of coals that could make the Engine hot enough to dry a drop of water in 20 seconds leaving afterwards the fire to go out of it self and if I would save time I should make a good fire that the heat might quickly come to dry a drop of water in 6 seconds and presently take away all the fire and so in all other Operations keeping still the proportion as 10 to 3 yet I confess this Rule is not demonstrated neither doth the matter in hand require such a Mathematical exactness When I say nothing of the inward pressure as in this Rule it is to be understood that it ought to be always equal EXPERIM. IX July 11. I took a Rabbet and having filled with it two Glass-pots and put some water in one and none in the other I kindled five ounces of coals and having prest the fire till a drop of water would dry away in 4 seconds I let the fire go out of it self The Vessels being cooled I found the Rabbets bones well softned in the Pot with water but in the other they were all very hard yet the flesh having been well seasoned it was as tender and savoury as any Pasty can be but in the Pot with water it relished not so well by a great deal By this Experiment I saw that Rabbets bones are harder than those of Mutton and I was more fully satisfied that water helps much the softning of bones EXPERIM. X. Propriety I took another Rabbet and having shut it up as in the former Experiment I kindled five ounces and half of coals but the paper in the joynt of it having been spoiled the inward pressure was not as strong again as the ordinary pressure of the Air because the water could get out and for that reason also the heat could not well be kept for notwithstanding the quantity of coals in this Experiment was greater the drop of water was twenty times longer evaporating than in the former Experiment So that we may reckon this for a Propriety of this Engine That the greater the inward pressure is the less quantity of coals is required to give a certain degree of heat The Rabbet was very tender but the bones were not at all softned no not in the Glass where I had put water but some that had been boiled the day before and put again to be made more ready were found very well softned By this Experiment I saw that although some boiled bones do not seem to be softned at all yet they have got a great preparation towards that though it doth not appear to sense EXPERIM. XI July 13. I took an old male and tame Rabbet which is ordinarily but a pitiful sort of meat I seasoned it and put it into two Glass-pots I kindled six ounces of coals and prest the fire till the drop of water would evaporate in less than 4 seconds the inward pressure was about six times stronger than the ordinary pressure of the Air. The fire being gone out of it self I found the Rabbet very ready and the bones softned and it was as savoury as young Rabbets use to be the Juyce of it turned to a good Gelly so that I think this to be the quantity of fire most fit to boil Rabbets EXPERIM. XII Proprieties August 12. I put
Pigeons into two little Glass-pots weighing them one after another before I inclosed them in their frame I prest the fire till the drop of water would dry away in 5 seconds and the inward pressure was ten times as strong as the ordinary pressure of the Air. The Vessels being cooled I found both the covers sticking pretty fast to their Pots so that it was apparent that the Air within the said Pots was rarified and that something had got out of them I weighed them one after the other being well dried as I had done before the boiling and I found that one of them wherein I had put by weight an eighth part less of meat than the Vessel could contain of water was exactly the same weight as before and the bones were very tender and the Juyce a strong Gelly without Empyreume The other Pot wherein I had put a greater weight of meat than it could hold of water was grown heavier and the Juyce in it was not so well congealed as in the other It is very like that the great quantity of meat being too much rarified in this Pot had opened the cover so as to admit some of the water from the Balneum Mariae which had increased the weight and diluted the Gelly but in the first Pot the rarefaction of the meat was able only to drive out a little Air without any sensible opening of the cover From this Experiment I think we may conclude that one Propriety of this Engine is That if we boil Pigeons so as to make the drop of water dry away in 5 seconds with an inward pressure ten times as strong as the ordinary pressure of the Air the weight of the meat in the Pot must be but 〈◊〉 of that which the Pot can hold seven pounds of meat for example in a Pot that can hold eight pounds of water for by that means the pressure in the Pot is as strong as in the Engine and yet nothing is lost In the sixteenth Experiment you may see that the water being taken in the same weight would do the same effect so that some people would think that all other bodies should be also taken in the same weight because those that would take up less room upon the score of their specifick gravity will by the same reason expand themselves so much the more but this would be a great mistake for I have tryed Chap. 6. Exper. 3. that Spirit of Wine though of a lesser specifick gravity than Vinegar will nevertheless rarifie a great deal more by heat Therefore if we will be very exact not to lose any thing and to have the intended pressure in the Pot we must find by experience how far and how powerfully other bodies will rarifie as in this Experiment I have found it for Pigeons to fill afterwards the Pot accordingly At the same time I had in another Engine some of the same Pigeons a boiling the heat was such that it dryed a drop of water in 3 seconds but the inward pressure was but five times as strong as the ordinary pressure of the Air. The Vessels being cooled I found the bones not quite so soft as in the other Engine though they had been in a greater heat yet they were almost all fit to be eaten This Experiment makes me believe that we may reckon this amongst the Proprieties of this Engine That it is almost the same thing to have the drop of water dry away in 3 seconds and five pressures as to have it dry away in 5 seconds and ten pressures in the Engine So people may find out by experience in any other case what quantity of pressure may do instead of a certain quantity of heat and if one had an exact Thermometer as I have said in Chap. 2. one might perhaps draw from thence great lights for other things I say besides that this Experiment shews that good Balnea Mariae fitted to hold great pressures would save a great deal of fire for we have seen Exper. 10. that the greater the inward pressure is the less coals will serve to bring the Engine to a certain heat and now we see that such a degree of heat raised with less coals may produce a greater effect than if we had been forced to bestow more coals for it where this pressure is wanting FISH EXPERIM. XIII June 15. I took a Macquerel and put it in a Glass-pot with green Goosberries I included the Pot in the Engine and with four ounces and two drams of coals I brought the heat to dry away the drop of water in 10 seconds and the inward pressure was seven times as strong as the ordinary pressure of the Air. The fire being gone out by little and little I found that the remaining coals weighed about two drams the fish was very ready and firm though the bones were so soft as not to be felt in eating the fish before it was boiled did weigh nine ounces and after boiling not above seven so that I had two ounces of good Juyce which would have been thrown away if the fish had been boiled after the ordinary way and moreover the taste was a great deal better the volatile Salts not having got away or been dissolved in water the Goose-berries had a very good taste and nothing of burning EXPERIM. XIV June 19. I made the same tryal with a Pike and I gave the fire as in the former Experiment the fish was found very ready and its flesh firm and the bones soft though they seemed somewhat harder than those of the Macquerel A Gentleman having tasted of this inquired whether it was the dissolving of the bones that made the fish so savoury this perswaded me that my thinking such fish better than ordinary was not out of preoccupation The Juyce of the Pike came to a strong Gelly which did not happen to that of the Macquerel I cannot tell whether this difference proceeded from the nature of the fish or from the temperature of the Air. EXPERIM. XV. June 20. I took a great Eel and having shut it up as I use I kindled four ounces and half of coals so that the drop of water did dry away in 6 seconds and the inward pressure was seven times stronger than the ordinary pressure of the Air the fire being gone out of it self the Eel was found very ready so was the skin and bones and all without Empyreume but its flesh was not so firm as that of other fishes the juyce did not congeal which I think did proceed from the excess of fire rather than from the nature of this fish since its skin seems very fit to make Gelly All these Experiments make me believe that all fishes may be made ready almost with the same degree of heat PULSES EXPERIM. XVI July 2. I put Beans in a Glass-pot some of which were raw and the other had been boiled already with Harts-horn I poured a little water into the pot to see the difference between those Beans that would
of the glass and then joyn them as before as exactly as we can the same may be applied to China-dishes Ivory Amber and such other brittle bodies EXPERIM. VI. July 1. I filled two glass-pots the one with one ounce of shavings of Harts horn and two ounces of water the other with an ounce of Whitings bones and two ounces of water Having continued the fire till the drop of water would dry away in 7 seconds with the inward pressure twelve times stronger than the ordinary pressure of the Air I took off the fire presently and the Vessels being cooled I found a very strong gelly in the Pot with Harts-horn I gave some of it to a person that makes such Gellies pretty often and she said that there must be something more in this than in hers because this had both smell and taste pretty strong but in hers there was neither of them I think this difference did proceed only from the Spirits and volatile Salts that are kept in by means of the Engine fastned with Screws and that fly away in the ordinary boiling and from thence it is very probable that this new gelly hath much more virtue in it The Harts-horn also was all very soft but in the ordinary way it is brought but to a powder that feels hard between the fingers In the other Pot the fish-bones were quite soft but the liquor would not congeal yet being dryed there was found some glue remaining but in small quantity and not so strong as that of Beef bones EXPERIM. VII July 2. I filled two glass-pots the one with half an ounce of Harts-horn and two ounces and half of water the other with bones and water in the same proportion as five to one and the bones were shaved as well as the Harts-horn Having augmented the fire till the drop of water would dry away in 5 seconds with ten pressures I took it off quickly the next day I opened the Vessels and found that in the pot with bones the liquor was but little thicker than water in the other there was a good gelly but not so strong as that in the foregoing Experiment I heated it again and as soon as it was melted I filtrated it and squeezed it as well as I could and I set the remainder a drying that remainder being dryed after a weeks time was found to weigh 2 ¾ drams so that all the congealing parts drawn from the Harts-horn did weigh but 1 ¼ dram and that had been enough to congeal 2 ½ ounces of liquor which is 16 times as much weight the liquor that had been filtrated did in a short time turn to a gelly much stronger than Harts-horn gelly uses to be therefore I believe I may be confident that a certain quantity of Harts-horn will congeal five times its weight of water and it may be by practising there will be found some degree of heat that will make more but though we could do no more yet this would be a considerable thing since in the ordinary ways the quantity of gelly is less by half and not so good and it requires much more fire and time and fresh water which is of consequence at Sea For although I must needs have water to make gelly after my way that water is not lost since it remains all in the gelly but if you make it after the ordinary way above three quarters of the water will evaporate away EXPERIM. VIII Having found by the last Experiment that Harts-horn doth yield so much gelly more than the bones do I had a mind to try whether the reason of it was not because the degree of heat was fit for Harts-horn but not strong enough for bones Therefore I repeated the same Experiment with the same circumstances but at this time I increased the fire till the drop of water would dry away in 4 seconds and the Vessels being cooled I found the gelly of Harts-horn pretty good still but the liquor upon the bones was not very thick yet I found some gelly after I had poured out gently the over-swimming liquor but that liquor weighed above an ounce so I thought that truly the bones do not contain so much congealing parts as Harts-horn doth Having filtrated and squeezed the matters of both my Pots I kept the remainders of them asunder each in a glass well stopt for fear they should dry and about two weeks after I found them fermented and of the same smell and taste as Parmezan Cheese and very fit to be eaten with bread When I had shewn such Harts-horn to the Royal Society they judged that in all likelihood being in that condition it would yield more Spirits and more easily than usually it doth The bones were in all things very like the Harts-horn and some time after worms were generated in them which did not happen to the Harts-horn so that it being usual to see worms generated in good rather than in bad Cheese it seems that in this the bones have some advantage above the Harts-horn as well as the Harts-horn is to be preferred to them for the quantity of gelly it yields Having found some difference both for the quantity and for the readiness in drawing Gellies from several Bodies as also for the strength of that kind of glue I believe there might be found a difference in several other Proprieties of them and seeing our bodies are but congealed liquors it is likely that if people would go on with this tryal and draw Gellies from several parts of the same Animal and from several Animals of the same kind but of different ages and from several kinds of Animals that live a great deal longer one than the other as from Harts and Rabbets and then if they would compare all the several proprieties of these Gellies with one another it is likely I say that it would be a great help towards making a better Theory than hitherto we have about the causes of the lastingness of our life and such a Theory would it may be prove of more consequence than many people are apt to believe From all the Experiments contained in this Chapter I think it very likely that if people would be perswaded to lay by Bones Gristles Tendons Feet and other parts of Animals that are solid enough to be kept without Salt whereof people throw away more than would be necessary to supply all the Ships that England hath at Sea the Ships might always be furnisht with better and cheaper Victuals than they use to have And I may say that such Victuals would take up less room too because they have a great deal more nourishment in them in proportion to their weight This is plain in Harts-horn which will make five times its weight of gelly which is accounted to be of a great nourishment and yet afterwards it will turn to a substance very like Cheese which cannot be eaten in great quantity EXPERIM. IX June 20. I boiled two Macquerels in the same manner as hath been described
Cochenille would give all its tincture without being grinded therefore he put three grains of Cochenille very entire into a glass pot with three ounces and half of water and at the same time he put into another pot some coarse Cochenille that is sold eight times cheaper than the other and therefore he put eight times greater quantity of it in proportion to the water Having increased the fire as in the former tryal with rubia tinctorum we found in the first glass that one of the grains of Cochenille had been quite dissolved and that the two remaining had lost all their colour and were turned black the liquor was of a fine red colour but in the second pot the tincture was stronger and deeper From this Experiment it appears that by the help of this Engine one may save all the labour of grinding the Cochenille and all the wasting of it and perhaps coarse Cochenille will give much more tincture than usually it doth I made a tryal with these Liquors to know whether the Pneumatick Engine would help Tinctures to penetrate better into the cloth I put a piece of cloth into one of the liquors and having set it so in Vacuo I saw according to my expectation that a great many bubbles of Air got out of the cloth so that I was in great hopes that the tincture getting into the place of that Air would penetrate every where yet having let in the Air again and exprest the humidity from the cloth I found that all the colour was gone too from whence I concluded that it is not enough to have the colour insinuate between the hairs of the cloth but that it must get into the hairs themselves and this cannot be done unless all the little particles every hair is made of be rarified and expanded by heat which is much more powerful for that than any Tacuum can be EXPERIM. IV. August 18. I put two pieces of cloth into two glass pots to one of them I added some tincture of coarse Cochenille and to the other Juvce of Prunes distilled after the manner described Chap. 6. Exper. 3. I prest the fire till the drop of water would dry away in 42 seconds with an inward pressure six times stronger than the ordinary pressure of the Air then I took off the sire quickly for fear the cloth should be spoiled the Vessels being cooled I found both the pieces of cloth good still and well dy'd the Juyce of Prunes having penetrated as well as the tincture of Cochenille but the tincture of it was of a deeper red and nearer to a brown colour the Juyce it self was much altered for it was Violet before it was grown also much more liquid and watry From this Experiment it appears that this Engine keeping things for a great while in a great heat without damage and hindring the most subtile parts from getting away as usually they do may be sit to insinuate into cloth such liquors as are reckoned to be too thick and glutinous as the Juyce of Plums is because for dying there is no need of good taste Mr. Mayre thinks there would be no need of an inward pot and so I believe the aperture of the outward Engine might be left lesser than the cavity as you may see Fig. 6. Yet if they would dye cloth in it the aperture HH should be left wide enough to convey the cloth into the cavity AA and this Engine should also hang in Aequilibrio by its Appendices CC for the conveniency of filling and emptying the same CHAP. VIII Experiments upon barder Bodies as Amber Ivory c. IHave made other Experiments upon harder bodies as Amber Ivory Cow's horn Tortoise-shells but because I have found nothing yet that may be brought to use I will not be tedious in relating the Particulars of those Experiments therefore I shall only set down some few observations which they afforded 1. Amber could never be melted whatever degree of heat I made use of though I filled the Engine with Pitch and Sand instead of water and I prest the cover with eight Screws instead of two I could indeed separate several substances from it as Balsam Fumes and Terrestreities but that cannot be called melted Amber since it hath-lost several proprieties belonging to Amber for if we dissolve these substances with Spirit of Turpentine they cannot be brought to any considerable hardness by evaporating the Spirit and an indifferent heat will soften them again 2. Mr. Boyle having given me some Copal Gum to try what it would do I found indeed that it could be melted without being much altered but when I would apply the same to facilitate the melting of Amber I found that it would not do I would for the same purpose make use of Gum Tragacanth Mastich and Rosin but it was all in vain so that I believe one may be sure that the melting of Amber requires a stronger and quicker heat than this Engine can give 3. Though Cows horn seems to be a more glutinous matter than bones are I could never make any gelly or glue with it though I have put the same over and over again in the Engine upon the fire even four times successively 4. I could never make Ivory soft and glutinous though I have boiled it several ways and in several Menstruums as Grease Oyl Beer and Water I could draw a fine and transparent Gelly from it but the body remained brittle 5. Tortoise-shell cannot be softned by boiling in Oyl but in Spirit of Wine it swells and hath a great many cavities like a Sponge 6. Cows horn and Tortoise-shell having been with water exposed to a heat that drys away the drop of water in 3 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air they come to be so soft that they do not grow hard again but in three or four days time and this perhaps might be of some use and give more conveniency to work those Materials than when they are heated only after the ordinary way but I must confess that they will afterwards be more brittle than before and I have seen once two pieces of Tortoise-shell that had been by boiling so well glued to one another that after they were hardned again they would rather break in other places than be separated CHAP. IX A Calculation of the price that a good big Engi ne may come to and of the profit it may afford BEcause people are loth to meddle with new Inventions lest the expence should be greater than the profit to be got by them I will subjoyn here a calculation of the price which a good Engine may come to and of the profit that may be got by it I have been at an Iron-mongers house and there I caused a cast Iron Pipe to be weighed This being six inches in Diameter and two foot long and without doubt strong enough to endure an inward pressure twenty times stronger than the ordinary pressure of the Air
This Pipe I say did weigh but 57 pounds so that such another Pipe 12 inches in Diameter and as strong proportionably to its bigness will weight but about 228 pounds But let a covered Vessel weigh 250 yet it will not come to 48 shillings seeing the Merchants can with good profit afford such Metal at two pence half penny a pound Now if the cover and the Vessel were ground to one another and that in a Country where Work-men are cheap the grinding will scarce come to two shillings Then the Iron pieces DD with four Screws lest two should not do enough and the Iron rod LM may be afforded much under five shillings especially if made in the Country and in numbers Five shillings would also be a great deal too much for setting the Pipe HH and sitting a Valve to it The inward Pot GG of cast Iron or glass or stone-pot might also be got under 20 shillings strong enough and big enough to hold 80 pounds of water I confess it would be a hard matter to make a Glass so big but instead of one they may make three or four to be set in the same Frame one above the other So that we may be sure that a Merchant may with good profit afford such Engines ready in good condition at 4 l. sterling apiece Now such an Engine is able to make above 50 pounds of the Gelly at a time and may do the same quantity at least twice in 24 hours for I have tryed that my great Engine which is 6 inches in diameter may in less than an hours time be heated enough to make Gelly of Bones therefore one may make 100 pounds of Gelly every day Now in Paris where people constantly keep Gelly ready to sell the price of it is 20 pence a pound but in London where they make none unless it be bespoken Apothecaries use to sell it at 2 shillings a pound therefore it would be a very good thing for the Publick if any one would sell Gellies for a groat a pound yet at that price the aforesaid Engine would make Gelly for above 33 shillings every day The fire will not come to six pence and the bones with some Harts-horn might be got cheap enough too since it is not necessary to shave them for this Engine and a little Sugar serves for Gellies yet let the expence come to 13 shillings a day there will be still 20 shillings profit for the Owner of the Engine and so in four days time he will be fully requited for his first expence and one man alone may at the same time keep five or six such Engines at work for several uses whereof some perhaps will prove more profitable than the making of Gellies Therefore we must not question but those that will set upon such things may make their own profit very well and at the same time do a great service to the Publick I have not therefore thought it right in a thing of so general use that a man by virtue of a Patent should hinder other people from working that may perhaps have more skill in doing things good and cheap and I have instructed Mr. Mayor a Founder in Old Bedlam how to make these Engines of cast Brass so that any body may see them and buy them of him POSTSCRIPT DOctor Edm. King Fellow of the Royal Society having got one of these Engines for a greater security and conveniency caused the rod LM to be fitted in L with a Joynt so that it must always fall upon the Pipe HH and there is no danger that the Valve P may slip off and spoil the Operation he hath also caused a Brick Furnace to be built on purpose so that I have lately tryed whether by that means the expence of coals would be less than in my Chimney-corner see pag. 6. but I have found contrary to my expectation that the expence is much greater in his Furnance the reason of which probably is because in his Furnace the coals did not at all touch the Engine but remained at a little distance below as in ordinary Sand-Furnaces the coals do not touch the Pot but in my Chimney the coals touch the Engine almost all along and thereby may the better heat it It is therefore likely that it would be better to build Furnaces so as to have the coals touch the Engine all along one side It would be better also to have them made of Iron plates because a Brick Furnace requires much fire to be throughly heated unless it be kept at work constantly Mean while the Doctor hath made several Experiments with his Engine having this conveniency that there is no need of blowing the fire Besides many good dishes of Meat and Fish he hath prepared several Medicines and found that in this Engine the Operation may be performed in less than the tenth part of the time that is required in his other Furnaces and yet some of them are much stronger than ordinary We have seen that Harts-horn in Winter time being boiled with twelve times as much water will turn it all to a Gelly so do the bones with above four times as much water which is at least as much again as I had found in Summer time Vpon this occasion I will mention two other Particulars which do not succeed in cold as in hot weather The first is the Fermentation of Bones spoken of Chap. 3. Exp. 8. which is not so well performed in Winter The second is the quantity of fire required in such Operations for I have found by my Engine that Mutton may be very well drest and the bones softned with five ounces of coals in Summer time but in Winter the same effect cannot be produced with less than six ounces and half We have seen that it is not necessary to put in the Engine all the water to be congealed but putting equal weight of bones and water after the Operation your water being mingled with three times as much fresh water will turn it all to a Gelly so the Gelly to be made with an Engine and therefore the profit to be got by it is much greater than I have said Chap. 9. I have found that an old Hat very bad and loosely made being imbibed with Gelly of Bones is become very firm and stiff so that it is likely if such Liquor should be used in making Hats they would be extraordinary good The Doctor 's Engine having already given occasion to these Experiments I doubt not but when the thing is made common a great many more Uses of it will be found in a short time FINIS
squeezed Goose-berries into another Glass with water and a little Sugar this in less than 24 hours began to ferment very violently and in a fortnight the liquor was pretty well clarified and good to drink but not so strong as that without water and I believe also it would have grown four in a short time This Experiment was made by guess and without Scales but I guest the fruit to have been about ½ of the weight of the water and the Sugar 〈◊〉 From this Experiment we see that the same fruit by means of this Engine may afford two sorts of Wine the one to keep long and the other to drink quickly EXPERIM. III. August 5. I took some of the Juyce of the Goose-berries above-mentioned in the time it did ferment most briskly and having put it into a little glass-pot and then in the Engine I continued the fire till the drop of water would dry away in 10 seconds with an inward pressure three times stronger than the ordinary pressure of the Air. I found that the liquor had got a taste near to that they call in France raisiné and it was pleasing to drink and apt to quench thirst Then that I might know whether the liquor had been much altered by boiling in the Engine I put some of it into a little glass and took some also out of the great Bottle that was a fermenting and having put it into another glass I included them both at the same time in Vacuo and found that the liquor which I had set upon the fire during its fermentation did not bubble so much as common water would do but the other liquor did at the very first suction rise all into bubbles From this Experiment I guess 1. That by boiling a Liquor whilst it ferments we may quickly take away the ill quality it hath to generate winds and cause pains in the Belly 2. That such a liquor would not hurt the Head neither as Wine doth because the Spirits are not yet quite so loose as they are in Wine and this appears because the Wine boils in some measure in Vacuo Boyliano but this liquor doth hardly yield any little bubbles 3. That such a liquor would not easily dye since the Spirits can so hardly extricate themselves And lastly I am very apt to believe that it would be a good nourishing and strengthning Drink since Bread is reckoned to be the staff of life which is put into the Oven even during its fermentation yet we must expect further Experiments before we can have any certainty of it in the mean time we may be sure that such drink may be got ready pretty soon EXPERIM. IV. August 17. I took Juyce of Plums distilled after the manner to be described Chap. 6. Exper. 3. and because it was thicker than that which is drawn without distilling for the Juyce which remains in the heat with the fruit is thereby continually attenuated I thought I should use more heat to attenuate the same therefore having shut it after the ordinary way I continued the fire till the drop of water would dry away in less than 2 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air I took away the fire and the Vessels being cooled I found contrary to my expectation that the Juyce was become almost all solid from the top to the bottom of the pot and that it was turned into a black stuff much burnt which could easily be powdered between ones fingers yet there were many cavities full with a very fluid liquor which had such an acrimony that the Tongue could hardly endure it so that the heat did work upon that Juyce almost the same effect as the Runnet doth upon Milk I have kept for two months together some of the same distilled Juyce of Plums and I found that it was not at all grown hard as that which had been in such a great heat was but it hath fermented very little in comparison with those that are more sluid This Experiment shews that the degree of heat is to be well observed in making Drink not to give too much nor too little and that distillations of Juyces may indeed prove very good to make clear Cakes Gellies Syrups c. but for Drinks ordinary boiling as I have said of Goose-berries will do better yet in time it may be such thick Juyces will make stronger Wines than thinner ones but I am afraid that will require many years EXPERIM. V. August 17 18 c. I kept Juyces of Plums to make the same Experiments as I have said of Goose berries but I think it needless to give the particulars of them because I learnt nothing new by them but that Damsons if they be not too ripe nor over-boiled will make Wine much stronger than Goose-berries and that having mingled a little Juyce that was a fermenting with a Bottle of Juyce newly drawn this mixture did like a Ferment hasten the fermentation in the said Bottle CHAP. VI. Experiments for Chymists EXPERIM. I. JVly 13. Dr. Slare Fellow of the Royal Society had a mind to try whether the Engine could not be useful to draw quickly the most stubborn Tinctures in Chymistry therefore we put into a little glass pot Salt of Tartar with rectified Spirit of Wine into another pot we put Amber with some of the same Spirit of Wine We continued the fire till the drop of water would dry away in 3 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air and then we did put it out presently The Vessels being cooled we found in the first pot that the tincture of Tartar was as strong as it could have been made in a months time after the ordinary way and its taste was lixivious in the other pot the tincture of Amber was a great deal stronger than usually it is EXPERIM. II. July 15. Dr. Slare had also a mind to make a tryal of the tincture of Antimony the fire was lighted by 10 〈◊〉 of the clock in the morning 1 continued it till the drop of water would dry away in 2 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air I took off some part of the fire so that the heat being diminished the drop of water did evaporate but in 3 seconds and nothing could get out of the Engine I kept the fire much about that same strength till 1 in the afternoon then I left it till about three of the clock at which time I found the Vessels much cooled and the fire almost out I lighted it again so that the drop of water would evaporate in 1 1 ◠second and then I saw again something get out through the little Valve P and I took off some of the fire till the drop of water would dry away but in 2 seconds and then the Engine was very tite again I let the fire go out of it self and found that the Vinegar had