. The microscope and its revelations. nemade by Carl Zeiss and illustrated in fig. 146. Of course the principle,as primarily in all the others, is that suggested by the late Mr. Mayall,and afterwards by Reichert. Two sliding pieces, mounted at rightangles to one another, are moved by means of two milled heads, S, pass along millimetre scales which serve to record any particularposition. The demand for these attachable stages is, we presume, consider- 184 THE H1>TKY AND DEVELOPMENT OF THE MICROSCOPE :iMr. for thrv are made by most leading opticians. The last mechanicalstage we illustr
. The microscope and its revelations. nemade by Carl Zeiss and illustrated in fig. 146. Of course the principle,as primarily in all the others, is that suggested by the late Mr. Mayall,and afterwards by Reichert. Two sliding pieces, mounted at rightangles to one another, are moved by means of two milled heads, S, pass along millimetre scales which serve to record any particularposition. The demand for these attachable stages is, we presume, consider- 184 THE H1>TKY AND DEVELOPMENT OF THE MICROSCOPE :iMr. for thrv are made by most leading opticians. The last mechanicalstage we illustrated is by Messrs. R. A: J. Beck, which is illustratedin H-. 117. It ha> vertical rack and pinion and horizontal screwmotion- \\itli graduated finer divisions. TII .Messrs. ISaiisch and Lomb, however, we are indebted for theint rod i ict ion of an atiaclialile stage in which the iris diaphragm is onthe plane of the stage. We illustrate this in fig. 147A. Its use witha condenser we do not c mimend. But especially when the illumina-. 1 • tchable mechanical stage. (3 full size.) (1895.) lion is daylight, and very critical results are not sought, it will lie ii-eful, and is admiralilv made. V. The sub-Stage is scarcely sec-mid in importance in a first-g microscope to the stage itself. It is intended to receive and enable us to use in lln- mpsl manner the optical and other apparatus employed to illuminate thr objects . with the found needful. Upon this much of the finest ^ ib the ] lerii microscope depends. •ompli-l, this a good sub-stage must have rectangular,anda rack-and pillion focussing adjustment. THE SUB-STAGE I85 The vertical and lateral movements need not be as elaborate asthose of the stage, since only a small movement in each direction isrequired. The object is to secure a centring motion, a motion thatwill make the optical axis of the sub-stage combinations continuouswith the optical axis of the objective. It must therefore be a steadymotion;
Size: 1455px × 1718px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
