BECKYS INTERNATIONAL STAND. 15 



the Ross model, but the pattern itself is quite unique, and 

 though of different construction to other forms, responds 

 satisfactorily to all the requirements of the microscopist. 



The stage has one inch of motion in two directions, by 

 means of the milled heads, and is capable of rotation round 

 the optical centre by means of a wheel and pinion. This 

 is combined with a very thin stage for oblique illumination 

 of objects, either by means of the mirror or the achromatic 

 prism. There is also a graduated silver circle, which can 

 be used as a goniometer or for a variety of purposes. 



The substage has rotary, vertical, and rectangular 

 motions, and both stages have for their foundation a solid 

 brass ring, which is firmly attached to the stem. This 

 stand is a specimen of excellent workmanship produced 

 regardless of cost, in order to give those who require and 

 can afford it perfection. 



With the best stand of Messrs. Beck we encounter a 

 difficulty. It was our intention at the outset to describe 

 those instruments furnished with swinging substages, under 

 a special heading, but the best or " International " stand of 

 Messrs. Beck being furnished with these additions, we feel 

 constrained to mention it here. See Fig. 7. 



All the instruments turned out from the factory of these 

 opticians are made upon the Jackson model (by whom 

 indeed it was first adopted) with the single exception of 

 their "popular" microscope, which is focussed on the 

 Ross principle. The " International " has a heavy brass 

 tripod for its base, upon which is placed a revolving gradu- 

 ated fitting, from which rise two pillars, together forming 

 the foot. Between these pillars is hung the limb which 

 carries the body at its upper end. In its centre the com- 

 pound stage is fixed, beneath which is a circular plate 

 carrying the swinging bar and substage. 



The stage itself is attached to the limb on a pivot, and 



