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THE MICROSCOPES OF 1894. 



movement to a minimum, getting rid of the only difficulty which 

 the small tripod form of foot is open to. 



Fig. 2 shows the instrument with the hind legs turned up pre- 

 paratory to being put away ; it will be seen that there is another 

 advantage in this form in that it takes up less room in packing, as 

 the legs fit close to the pillar of the microscope. 



Messrs. Swift's Three-Legged Microscope. 



Previous to bringing out their four-legged form just referred to, 

 these makers produced this form of microscope (Fig. 3). With 

 the exception of the foot, the previous description is applicable to 

 this stand. The illustration shows the microscope in an horizontal 

 position, as used in photo-micrography. It will now be seen that 

 the horse-shoe platform in this and the preceding stand is extremely 

 serviceable, as it allows the pillar of the instrument to rest firmly 

 upon it, thus rendering the stand very rigid. 



Messrs. Swift's Mechanical Stage. 



This stage is simply unique, and came as a surprise to most 

 microscopists. It is the first time, we believe, that friction wheels 

 have been used for microscopical apparatus. The figure will 

 illustrate the apparatus in question better than any description. It 

 will be seen that the object-stage runs in grooves let into the side 



Fig. 4. 

 of the horse-shoe stage. The slide, which rests on the stage of 

 the stand, is pressed by a wheel at the end of a powerful spring 

 against two small wheels on the inner edge of the object-stage. 

 Transverse motion is imparted to the slide by a turning milled 



