The microscope made easy.

Date:
[1750]
Catalogue details

Licence: Public Domain Mark

Credit: The microscope made easy. Source: Wellcome Collection.

    4/10 (page 52)
    *fhe Universal Magazine 52 ation of the glares in the firu&ure of this j:e<vj microicope. A reprefents the box, in which is contained all the apparatus, when packed up for carriage, and ferves for a bafe or pedeflal to iupport the inftru- ment when erected for obfervation. On the top of this box is faflened a brafs plate or dove-tail, which the bafe of the brafs pillar B Hides on, and is thereby fixed immoveable. Note. Take off the brafs plate which Hides over the dove-tail, to preferve its edges, before you can erect the piftar. C is the body of this microicope, fixed in a circular collar at a a, and may be taken in and out at pleafure. See you fix it tight. 1) is a horizon¬ tal plate or Hage, on which any of the parts for holding the objedls for ob¬ servation are placed. It may be taken off at b, and is fixed to a fquare brafs collar, which moves up and down the pillar, to render it more eafy in its motion for adjufling, the body C be¬ ing fixed without any motion. And on the top of this llage is a thin round plate, under which the ivory Jliders mull be placed, it being made with a proper fpring, fo as to give way for their reception : and under the llage is a proper cavity which fprings in the fame manner, to receive a glafs tube. Of which parts we have faid enough at No. 1. and No. 17. infg. I. F is a femicircular brafs frame in- doling a concave and a plain glafs, which, properly direded, throws up the light to the objeft fixed on the llage.— The Hem of this femicircle mull be fixed in the hole 1 or 2, as the cbfer- ver chufes. Though, it is thought, the three greateft magnifiers will require it at 1. \ G Is a double convex lens, which, turning on two ferews, tranfmits light to examine opake objects. The long cylindrical part <•, is placed in the fpring-tube d, faflened to one corner of the Huge. I he {‘Amt Jliders and tube for view¬ ing different ofcjefls are ufed in this, as in the Tingle microfcope, where they are dgffcribed under No. 1. 17. No. 18. Is a long wire with a worm at one end, contrived to pull out the cotton kept in the tubes to prevent their breaking, and to clean them with cotton, when neceffary. No. 16. Is a fmall lens or magnifier in a brafs cell, which is made to ferew on at the end of the brafs fnout at K, of which glaffes there are fix of different focus's, to be ufed at diferetion, accord¬ ing to the fize of the objefl. No. 10. Is a brafs cone to fallen in the fhank under the middle of the llage, when any very tranfparentobjecls are viewed with the ill, 2d, or 3d magnifiers (See No. zi. fig. III.) particularly in view¬ ing the circulation of the blood. No. 2. Is a hollow cylinder with its fides open ; to the end of which is ferewed a concave filver fpeculum b, having a round hole in the middle of it. This cylinder Hiding over the fnou: of the microfcope m, and the top edge fet to the mark correfponding with the mark on the magnifier ufed, a firong light becomes reflected from the filver Jpe- culum on any opake body under ex¬ amination. The concave or plain mir¬ ror, in this as well as in all other ob- fervations, may be either of them ufed as you like bell. No. 5. Is the long lleel wire with a pair of pincers, de- feribed in fig. III. Here it Hides back¬ wards and forwards in a fpring tube n, fafiened to a joint with a fhort lhank that puts into a round hole of the flit in the Hage D. No. 4. Is a little block of ivory, white at one end, and black at the o- ther, for objects to be placed on ac¬ cording to their colours, with a hole through the middle, to fdek it on the point of the wire 5. On this block, fait, fa’nd, or fuch like objects, are fixed with gum, if they will not lie other wife. No. 7. Is a round box to coniine final! infefts between two glal- fes, one of which is concave, the other plain. This box or cell muH be placed over the hole in the center of the Hage, firfl having the hole covered with the plain glafs, No. 6. and then move it about till you bring the objedl exa&ly under