. The microscope and its revelations. hown at Q. This stage is strictlya micrometer one, hav-ing rectangular move-ments and a, fine ad-justment, the move-ments being accom-plished by fine-threadedscrews, the milled headsof which are graduated. The mirror, E, is adouble one. and can lieraised or depressed byrack and pinion; it isalso capable of removal,and an apparatus forholding large opaque.(>1 >jects, such as minerals,can be substituted for accessory instru-ments are very numer-ous, and amongst the FlG< large universal microscope as usedmore remarkable may by Quek
. The microscope and its revelations. hown at Q. This stage is strictlya micrometer one, hav-ing rectangular move-ments and a, fine ad-justment, the move-ments being accom-plished by fine-threadedscrews, the milled headsof which are graduated. The mirror, E, is adouble one. and can lieraised or depressed byrack and pinion; it isalso capable of removal,and an apparatus forholding large opaque.(>1 >jects, such as minerals,can be substituted for accessory instru-ments are very numer-ous, and amongst the FlG< large universal microscope as usedmore remarkable may by Quekett (1780J. be mentioned a tube, M, containing a speculum, which can take the place of the tube. R. and soform a reflecting microscope. The apparatus for holding animalculesor other live objects, which is represented at 8, as well as a plate o|glass six inches in diameter, with four concave wells ground in it,can be applied to the stage, so that each well may be brought insuccession under the magnifying power. The lenses belonging to. 142 THE HISTORY AND DEVELOPMENT OF THE MICROSCOPE this microscope are twenty-four in number; they vary in focallength from lour inches to one-tenth of an inch; ten of them aresupplied \vith Lieberkiihns. A small arm, capable of carrying singlelenses, can lie applied at T, and when turned over the stage the in-strument becomes a single microscope ; there are four lenses suitablefor this purpose, their focal length varying from y^th to TLth of aninch. The performance of all the lenses is excellent, and no painsappear to have been spared in their construction. There arenumerous other pieces of accessory apparatus, all remarkable for thebeauty of their workmanship. Martin not only in this way greatly advanced the ;-hanical arrangements of the microscope, but he improved the optical part. He used a Huvgheniaii eye-piece on the telescopeformula, where the focus of the eye-lens was that of the field-lens:!. and the distance between them 2; but ins
Size: 1152px × 2169px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
