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ARTS, SCIENCES, AND MISCELLANEOUS
ENLARGED AND IMPROVED.
THE SIXTH EDITION.
Illustrated with nearly sir hundred Engravings.
INDOCTI DISCANT; AMENT MEMINISSE PERITI.
AND HURST, ROBINSON, AND COMPANY, 90, CHEAPSIDE,
HIST ANTIQ. WALFORD 10-8.68 711776-129 ADD VOL.
M I C
the plates in a right position and counteract the long scupe.
the seventh magnifier, set in the manner of a little For the principles on which the construction of mi- barrel, to be beld in the hand for the viewing of any croscopes depends, see Optics. Ia the present article, langer object. M is a flat slip of ivory, called a it is intended to describe the finished instrument, with slider, with four round holes through it, wherein to all its varied apparatus, according to the latest improve- place objects between two pieces of glass or Muscovy ments; and to illastrate by proper details its uses and talc, as they appear at d d d d. Six such sliders, and importance.
one of brass, are usually sold with this mioroscope,
some with objects placed in them, and others empty I. of SINGLE Microscopes.
for viewing any thing that may offer : but whoever
pleases to make a collection, may bave as many as he The famous microscopes made use of by Mr Leeu- desires. The brass slider is to confine any small object, wenhoeck, were all, as Mr Baker assures us, of the that it may be viewed without crushing or destroying single kind, and the construction of them was the most it. N is a tube of glass contrived to confine living ob simple possible; each consisting only of a single lens set jects, such as frogs, fishes, &c. in order to discover the between two plates of silver, perforated with a small circulation of the blood. All these are contained in a hole, with a moveable pin before it to place the object little neat box of fish-skin or mahogany, very convenient on and adjust it to the eye of the beholder. He informs for carrying in the pocket. us also, that lenses only, and not globules, were used in When an object is to be viewed, thrust the ivory every one of these microscopes.
slider, in which the said object is placed, between the 1. The single microscope now most generally known two dlat brass plates EE: observing always to put COCKRIVII, and used is that called Wilson's Pocket Microscope. The that side of the slider where the brass rings are farFig.ro body is made of brass, ivory, or silver, and is repre- thest from the eye. Then screw on the magnifying
sented by AA, BB. CC is a long fine threaded male glass you intend to use, at the end of the instrument
. And though the greatest magnifiers can show