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“XXIV. x. A B, I call the Frame os the Microscope. It may be about .A »'aur-Mu-n-is of an Inch in thicknels. At A there is a fhtall Hole, near jo of an Inch-hj’?''^^Diameter, this ferves for the Aperture of the Water, being in the Center of Grjy."n. 221.a larger Spherical Cavity, about § of an Inch Diameter, and in depth forne-?- 24 1. -2z.

what more than half the thicknesi of the Brass. Opposite to this, at the other ? ‘fide, there is another Concave but half the breadth of the former ; which is r,?. 101.lb deep, as to reduce the Circumference of the (mali Hole in the Center, toalmost a sharp edge. In thefc Cavities the Water is to be placed, being takentrpon a Pin, or sarge Needle, and conveyed into them till there be formcd aDouble Convex Lens of Water; which, by the Concaves being of differentDiameters, will be Equivalent to a Double Convex, of unequal Convexities.

By this means, I find the Objeci: is rendred more Distinct than by a Plano-convex of Water, or by a Double one, formcd on the plain Surface of theMetal.

C D E, is the Supporter, whereon to place the Object ; if it be Water,in the Hole G; if a Solid Object, on the Point F. This is fixed to theFrame of the Microscope, by the Skrew E, w'nere’tis bent upwards, that itsupper part may stand at a distance from the Frame ; ’tis moveable on theSkrew as a Center, to the end that cither the Hole C, or the Point F, maybe expofed before the Microscope ; and that the Object may be brought to,and fixed in its Focus. There is another Skrew, about half an Inch in length,which goes through the round Piate into the Frame of the Microscope A E,the Skrew and Piate taking hold of the Supporter about D, where there is aSiit fbniewhat larger than the Diameter of the Skrew, which is requisite forthe adniiifion of the Hole C, or Point F, according to the Nature of theObject, into the Focus of the Glafs ; for by turning the Skrew G, the Sup-porter is carried to or from the fame, which may be fboner done, if whilstone turn the Skrew with one hand, the other hold the Microscope by theend B, and one continue looking through the Water till the Object be fecnmoli distinctly.

The Supporter mu st be made of a thin piece of Brass well hammered,that by its Spring it may the better follow the Motion of the Skrew. Ichofe rather to fix the Supporter by the Skrew E, than by a Rivet; becaufe itmay now, by help of a Knife, be unskrewed, and by the other Skrew G, bebrought dose to the Frame of the Microscope without weakening its Spring,and fö become more conveniently Portable. If the Hole at G be fiiled "

wich Water, but not f b as to be Spherical; all Objects that will bear it, arefeen therein more distinctly.

1. Having obferved fönte Irregulär Particles in Globulesof Glafs, and find-^4--°,---,. ibiJ.ing them Dillinct, but prodigioully Magnified, v/hen held clole to the Eye, a - ' 2 - 1 - •

I concluded that if I conveyed a fhtall Globule of Water to my Eye, andthat there were any opacous or lels transparent Particles than the Water there-in, I ntight fee them Distinctly. I therefore took on a Pin a fhtall Portion. - »-

ol Water, which 1 knew to have in it fönte minute Animals, and laid it on ' ' , '

the end of a fmall piece of Brass \A'irc (there lay then by nte) of about iö

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