Section 86

To fee in a plain Cjlafs that which appears no where,
I have often much delighted my friends , and made them admire with this Glafc Provide thirty or forty little Tables ready , of a foot and half long, and two fin^r« bread , and a third part of a finger thick ; fo artificially hewed, that the thictosefs may be upon the one fide, and the thinnefs ©n the other fide, like the edge of a knife.
Place
Of Jlrange (jlajfes. 57 p
Place all thefe boards together , that the folid parts may Hand altogether, as to make a perfect plain : Then paiac your own Picture, or of fome other thing upon it : yec by this artifice and great obfervation, that if the Image be neer the Glafs, it mult be drawn as it were afar off. If you would have it far diftant , let the forehead be unmeafurably long, the nofe fomcwhat longer , and the mouth, and the chin, like- wife. The manner how to draw this Form exactly in Tables , 1 faid in my Opticks. When the Image is now defcribed, fatten the little boards upon a plain Table , that the head may be fet downwards , and the chin upwards ; and place thefirft Table after the fecond, and the fecond after the third , till they be all faftned, Hang the Table above a mans height, that no man may fee into it , above the degrees of the Tables : and place" a Glafs over this , diftant two foot from the Table , fo long lift- ing it up , and putting it down till you fee the perfect Tmage. Now when any man comes neer the Glafs to fee his own Image , he fhall fee the Image of fome other thing that appears no where. In the breadth of the Tables you may draw fome Picture, left they fhculd give fome occafion to fufpeet.
Chap. XXI. How Spettasles are made,
y\/E fee that Spectacles were very neceffary fcr the operations already fpoken of, or elfe lenticular Cryftals, and without thefe no wonders can be done. 1c remains now to teach you how Spectacles and Looking- glaffes are made , that every man may provide them for his ufe. In Germany there are made Glafs-balls, whofe diameter is a foot long, or there abouts. The Ball is marked wi:h the Emril- ftone round, and is fo cut into many fmall circles , and they are brought to Venice. Here with a handle of Wood arc theyglewedon, byColophonia melted: And if you will make Convex Spectacles, youmuft have a hollow irondifh , that is a porti- on of a great Sphere, as you will have your Spectacles more or iefs Convex ; and the difh muft be perfectly polifbed. But if we leek for Concave Spectacles ; let there be an Iron-ball, like tothofewe ihoot with Gun-powder from the great Brafs Ca- non : the fuperbcies wherecf is two, or three foot about : Upon the Difh, or Ball there is ftrewed white-fand , that comes from Vincentia, commonly called Saldame, and with water it is forcibly rubbed between our hands , and that fo long until the fuperficies of that circle {hall receive the Form of the Difh, namely, a Convex fupre- ficies,orelfe a Concave fuperficies upon the fuperficies of the Ball , that it may fit the fuperficies of it exactly. When that is done, heat the handle at a foft fire, and take off the Spectacle from it , and joyn the otfier fide of it to the fame handle with Colophonia,and work as ycu did before , that on both fides it may receive a Con- cave cr Convex fuperficies : then rubbing it over again with the powder of Tripolis, that ir may be exactly polifhed j when it is perfectly polifhed , you fhall make it perfpicuous thus. Theyfaften a woollen-cloth upon wood; and upon this they fprinkle water of Depart, and powder of Tripolis ; and by rubbing it diligently, you fhall fee it take a perre& Glafj. Thus arc your great Lenticulars , and Spectacles made at Venice,
Chap. XXII.
How upon plain Concave and Convex Clafes , the foils are laid on and they are banded,
NOw it remains that T fpeak of fome few things,not to be overpafled of the band- ing of Convex Glaffes , and of foiling plain Glaffcs, and Convex Glaffes , that fo I may fet down the perfect Science of Looking-glaffes. Firft, for the terminating of Looking glaffes , that are made of Cryftal and Glafs, then of other mixtures , and polifhings, that a knowing Artificer may know, and know how to make them : For though amoneft many thing;?, that fhew the Images of things , as water , fome Jewels, and polifhed Metal doit; yet nothing doth fo plainly reprefent Images,
E c e a as
380 Natural Magick. "Bool^ 17.
as Lead foil'd upon Glafs. Plain Looking- glaffcs arc prepared of Cryftal, and of Glafs ; thofc of Cryftal are poliflhed by wheels, and require another Artifice. But at Venice
How Glafs Looking- glares are madey
I have fcenic. % They take the melted Glafs out with an Iron ; with their blaft they frame an empty Pillar ; they open it on one fide with their tongs , and whilft it is red hot they lay it upon a plain plate of Iron , that is equally made ; and they put it into the furnace again, to make it fofter ; and that it may get the perfect plainnefs of the iron plate , they leave it over the furnace to ccol by degrees ; When it is cool, they do thus
Pol,(b plain GLffes.
Theyfaflen it upon a plain Table with Gyp; underneath lyeth a moft polite plain plate of iron ; they caft upon it the forefaid fand j they rub it with water by a (tick, leaning thereon, until it bcperfe&ly plain; they take it from the Table, and glew it on the other fide, to polifh them both : then they make them perfpicuous, as I faid
they did. Now will I fhew
To terminate plain Glafs LoektHg-glaffes, Glafs or Cryftal Looking-glaffes , when they are made plain aud equal , the Artift makes a foil of the famebignefs of Tin, that is level and thin, as perfectly as he can, For if Cryftal or Glafs had no foil of Lead behind it, by its ftrength and thicknefs ic could never terminate our fight, norftay the Image Printed upon it, but it would let it flip away j for Glafs is pure and tranfparent , and fo would not contain it , by reafon of its brightnefs ; and fo the Image would vanifh in it , as light in the Sun. Wherefore uponthisfoil you (hall wipe over with Quicksilver, by the means of a Hares fcor, that it may appear all as Silver: and when you fee it fafton the fuperfi- cies, you fhall put it upon a fair white paper , and (o upon the Glafs ; but firft made clean with a linen clout, aud polifhed : for if you handle it with your hands , ihle foil will not flick to it: with your left hand prefs down the Glafs, and with the right take away the Paper, that the foil may cleave every where, and they bind faft toge- ther ; laying a weight upon it for feme hours, and fo let it (land and ftir it nor. Now I will {hew
How a foil is put upon a Concave Glajs,
But it is more laborious to lay a foil on a Concave- Glafs : Prepare then a foil of the bignefs of your Glafs, that yon fhall lay upon the Convex fupeificies ; and holding it faft with a finger of your left hand upon the Centre , with your right hacd ycu fhall fit the foil rcund about, and fhall extend it on the laid fuperficies, until it become of the fame fotm with that convex fuperficies , and flick every where even unto it. Then of moill Gyp fhall you prepare a form of the Glafs , namely , by pcurirg Gyp npen the Convex fuperficies ; and when the Gyp is dry, ycu have the form. Upon the form extend a foil ©f Tin , and let it agree perfectly with the foim every where, becaufe the foim and the foil are made after the fame fuperficies : ftrew quick'filver upon the foil, and as I faid, make it flick by means of a Hares foot. The Artifts call this Avivarei put paper upon it , andpreflmg this upon the Glafs , take away the p*f er ; when you kne w it flicks faft, take away your hand, and lay on a weight, and after rake it away, but with a careful balancing of your band, left it take wind, and that the quick filver may all flick faft every where. Now remains how
To terminate finvex-Glajfes. Make Glafs Balls, but of rure Glaf?,and without bladders as much as ycu car, as the rr ceivers for dtf illations . and from the hollow iron that it is blown in by , let this liquid moiflure be projected , mmely, cf Antimony and Lead ; but the Antimony mnftbe melted twice or thrice, ard purged, ardcaft Colop honia in. So flir the rtiixtcre in the hollow vtflel, and what remains caft forth: andfo in Gumany they make Comex-Glaffcs. Chap.
Of ftrange (jlajfes.
Chap. XXIII.
How Metal Lookifg-Glajfes are made.
. l
BUt MetaUGlaffes are made another way. Wherefore if a Parabolical-Glafs be to be made, draw a Parabolical line upon a brafs or wooden Table ; what is without it, muft be filed away, that it may be equal, fmooth, and polilhcd : fatten ic upon an Axis in the middle, and fit it with Inftruments, that maybe fitly turned about, let there be clay with ftraw under it , made up with dung, that the Table be- ing turned about , it may receive a Concave form exa&ly ; then let it dry, ftrcw ames upon it , and plaifter clay above thar,of a convenient thicknefs ; let it dry by the fire, or if you will, by heat of the Sun, takeitcflf, for it will eafilypart from the allies : unite them together , that as much fpacemay be between both forms, as you think fit , for the thicknefs of the Glafs : when it is dry , cover it with this, leaving an open orifice on the top, and fome breathing places , that the Air may breathe forth at if. Then make fuch a miiture } let them be put into a new pot that will en* durethe fire , and lute it well within , that it may hold the fafter ; let it dry well, and do this twice or thrice over : fet it to the fire, and melt in it two pounds of Tar- tar, and as many of white Arfenick ; when you fee them fume, pour in fifty pounds ofoldbrafs, often ufed, and let it melt fix or feven times, that it may be pure and eleanfed ; then adde twenty five pounds of Englrfh Pewter, and let them melt toge- ther : draw forth fome little of the mixture with fome Iron, and try it, whether it be brittle or hard ; i& it be brittle,put in more Brafs ; if too hard, put in Pewter: or elfe let it boil,that fome part of the Pewter may evaporate : when it is come to the tem- per it fhould be , caft upon it two ounces of Borax , and let it alone till it diffolvc into fmoke; then caft it into your Mold.and let it cool : When k is cool, rub it with a Pumice.ftcne , then with powder of Emril. When you fee that the fuperficies is perfectly polilhed and equal , rub it over with Tripolis. Laftly, make it bright and Chining with burnt Tin ; nioft adde a third part of Pewter to the Brafs , that the mils may be the harder, and become more perfpicuous.
THE
THE
EIGHTEENTH BOOK
O F
Natural Magick :
Treating of things heavy and light.
The Proihi.
MAnj miracles worth relating and to be contemplated, do offer themselves when 1 be* gin to defer the heavy and light ; and theft things may be af plied to very neceffary and prof table ufes, and if any man ft all more deeply confder thife things%he may invent many new things : that may be employed for very prof table ends, "Hsxt after thefe follow wind InftrnmentS) that are almoji ' from the fame reafon.
Chap. I.
That heavy things do not defemd in the fame degree 'fgravity^ nor light things afcend.
Efore I (hall come to what I intend to demonftrate, I omit premife fomethings neceffary , and fee down fome anions , without the knowledge whereof we can make no proof, nor demonftration. I call that heavy that defcends to the Centre, and I fay it is fo much the heavior the fooner it defcends, contrarily ; that is light that afcends from the Centre, and the lighter that afcends foonetf. I fay that bodies yield one to the other, and do not penetrate one the other , as wine and water , and other liquors : Moreover, this action muft be pre- mifed, that there is no body that is heavy in its own kind , as water in the element of water , ©r Air in Air. Alfo vacuum is fo abhorred by Nature , that the world would fooner be pulled afunder than any vacuity can be admitted: and from this re- pugnancy of vaeutm proceeds almoft thecaufeof all wonderful things, which it may be I fhall Chew in a Book on this Subject. It is the force of vacmm that makes heavy things afcend , and light things defcend contrary to the rule of Nature , fo neceffary it is that there can be nothiog in the world without a Body. Therefore thefe things
being prcmifed,I fhall defcend to fomethings. And firft, a mo(i heavy body four up in a vef- fel, whofe mouth is turned downwards into fome liquor that is heavior , or of the fame kind. I fay it will not defcend. Let the vef- fel turned with the mou-h downwards, be A B filled with watr r, the mouth of it be- neath mu '\ be put into a broad mouth*d veflel C D full of water, be it with the fame liquor, or with another that is heavior. I fay the water will not defcend out of the veflel A B. Forfhouldthe water contained in the veflel A B defcend, itmuft needs be heavior than the water contain'd in the broad mouth'd vef- fcl C D, which I faid was of the fame kind or
heavior,
3«j
heavior , if then it fhould fall down it would be againft the firft a&ion. The fame would fall out if both veffels were filled with wine or water. For if the water con- tained in the veffel A B, fliould defcenci into the place of CD, there would remain vacuity in A being there is no place for the air to come in and that were againft the fecond axiom : wherefore by reafon of vacuum, and becaufe the body is no heavior, it falls not into the bowl beneath. But fhould one make a hole in the bottom of the veffel A, that the air might come in , no doubt the water would not fall down into thebazon: Alfo, if iheveltelA B were filled with anyli^ht liquor, and the broad bazon with one that is heavior , they would not ftir from their place?. Let there- fore the veffel A B be filled wiih wine , and the mouth of it turned downwards into a bazon full of water ; I fay both liquors will keep their places , and will not min- gle; for fhould the wine defcend, either Wf«»wmuft needs be in the body A, or a heavy body muft afcend cut of the veffel C D , which would be againft the Nature of Gravity : and the fecond axiom, namely, that heavy fhould afcend , and light de- fcend: wherefore they will not remove from their places. Hence comes that which is often done by great drinkers and gluttons,who pour by dropsjinto a cuphalf full of water, o much wine as will fill the cup, they come foclofe together, that oncly a line parts thofe liquors. And thofe that would fooner cool their wine,they dip a Vial full of wine into a veffel full of water,with the mouth turned downward, and hold it down under the water : for when the water toucheth the fuperfictes of the whje9 they can- not mingle , and the wine grows fooner cool » though it is neceffary that the Vial fliould be lifted up to the fuperficies of the water , and fuddenly turned abour, pour- ed forth and drank ; then fill them agiin , and fet in the bottle as before. From this advantage I compliin of thofe , who firft drink water, then pour in wine , for wine being the lighter, and water the heavior, they can hardly mingle : wherefore fome drink at firft the ftrmgeft wine, then mingled, and laft of all, water. At great mens Tables they firft bring wine in a Glafs , then they pour in water, that the water by its weight may mingle with the wine, and get to the bottom, and taft equally. Thee* fhrtftui bids men firft pour in wine, then water.
\7"\7"Heii friends drink together , if we would by fuch a merry deceit delude the guefts that are ignorant of the caufe hereof, we may provoke them to drink with fuch a Cup ; Let there be a great Cup made like a tunnel, let the mouth be broad above, and beneath narrow Pyramidally , and let it be joyn'd to a Glafs- Ball, by a narrow mouth; Firft pour in water, till the whole Ball be filled ; then put in wine by degrees, which by reafon of the narrownefs of the mouth will not mingle, and the water is heavy,and the wine lighter ; He that drinks firft,fhall drink the wine; then give it vowr f rind to drink, for he fhall drink nothing but water. But if your friend fha'l challenge you to drink thus with him , and will have you drink firft; fill the Ball of the Cup with wine, and pour water upon it , and ftay awhile , and hold him in difcourfe ; for the water will fink down by the narrow mouth , and the wine by degrees will afcend as much , and you fhall fee the wine come up through the middle of the water, and the water defcend through the middle of the wine , and fink to the bottom ; fo they change their places: when you know that the water is gone down , and the wine ccme up, then drink , for you fhall drink the wine , and your friend fhall drink the water. Hence it is , that to great inconvenience of thofe that drink it , when we plunge our wine into a well in veffels of earth , or brafs, ill ftopt,tocoolit, the water being the heavior comes in at the leaf! chink, and for- ceth out the wine , fo in a little time the veffel is full of water, and the wine is gone, that there is not the leaft tafte of wine in it t wherefore ftop the mouth very clofe.