The microscope made easy.

Date:
[1750]
Catalogue details

Licence: Public Domain Mark

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

    1/10 (page 49)
    To the Proprietors of the Universal Magazine. Gentlemen, Tour ready Conveyance of ufeful Knowledge to the Public gives me Expectations of finding the following Draughts and Explanations of the befi Kinds of Mi- crofcopes in your Magazine, as foon as you jhall fee convenient. By which I intend to make that ufeful Infrumcnt eafy, for the Infraction of fuel:, particu¬ larly, as define to fearch into the Wonders of the minute Creation; though they are not acquainted with Optics. The Microscope made eafy. With a true Reprefentation of their beft Kinds, and of feme Objects, in a large Copper-Plate neatly engraved. A Microfcope is an inftrument con¬ trived by art, to make fmall objects appear larger than they do to the naked eye, by the help of convex glafies. An invention not to be traced higher than the year 1621 ; fince which time it has been greatly im¬ proved. So that now we have both Jingle and double microfeopes; and thefe again are fubdivided by other names. The fingle microfcope has but one lens or iinall glafs, and fhews the ob¬ ject nearer at hand, and rather more diftinCl. The double is a combination of two or more fmall glafles, and re- prefents a larger field, or more of an object, equally magnified, at one view. ‘ One remarkable difference, fays i Mr. Henry Baker, in the effect of * thefe two inftruments is, that an ob- ‘ jeCt, viewed through a fingle convex * glafs, appears magnified, in the fame * pofition exaCtly, as when feen by the ‘ naked eye ; but when viewed thro’ f a double microfcope, compofed of three * convex glades, all parts of it become * inverted ; that is, the top of the ob- ‘ ject appears at bottom ; the right * fide, on the left ; and every part in * the place moil oppofite to its natural * and true pofition : the lights and * fhades being alfo inverted, the fink- * ing parts appear to rife, and the ri- * fing parts to fink in.’ Yet it is diffi¬ cult to determine which of thefe to recommend, fince each affords a dif¬ ferent kind of pleafure. And, there¬ fore, I have given you the fpedmens of each fort under divers fonns, with their aeferiptions. Numb. XXXVIII. Vol. VI. The fingle pocket microfcope, ffg. I. in the plate, gives honour to Mr. iYilfcn, its inventor, and is thus deferibed : A A. BB. fhew the form of its body made of filver, brafs, or ivory, Cfc. C C, a long-threaded male ferew turn¬ ing .into the faid body. E E, three thin brafs plates within the body; one of which is bent femicircularly in the middle, fo as to form an arched cavi¬ ty to receive a glafs tube : the other two are flat, and receive and hold the Aiders between them. F, a piece of wood or ivory arched in the manner of the femicircular plate, and cement¬ ed thereunto. G, the other end of the body, where a hollow female ferew is adapted to receive the different mag¬ nifiers. H, a fpiral fpring of ffecl be¬ tween the end G and the brafs plates, to keep the plates in a right pofition, and to counteract againff the long ferew C C. The turned handle is made to ferew on and off at pleafure. Note. To this microfcope belong fe- ven different magnifying glafies, the lowed: number being the greateff mag¬ nifier : fix of them are fet in filver, brafs, ivory, &c. as in No. 1/.. Ths feventh is like a little barrel. No. 13. to be held in the hand for the viewing any larger objeCt. No. 1. Is a fiat flip of ivory, called a fiider, with four round holes through it, wherein to place objeCts between two glafies or pieces of Mufeovy talc. No. 19. Is a forceps or pair of plyars for taking up objects, and adjuffing them to the glaf- fes. No. 3. Is a little hair-bruih or pencil to dull the glafft ies, or to take Ji