DESCRIPTION OK DR. GOFUNg's ENGISCOPK. 177 



Le Baillif, at Paris ; but we have long been in the habit 

 of using cones for the same purpose in England. 



Figure 27 is a contractor, which drops into the sink 

 formed in the aperture of the stage, when too large for 

 carrying on dissections, or other operations of a similar 

 nature ; it has two bayonet-catches, which secure it by 

 being turned one quarter round : into the aperture of 

 this latter piece, a small slider-holder may be advan- 

 tageously fixed (to be used with the Amician Engiscope 

 or the simple microscope), which should likewise be 

 made to fix to the top of the false stage, figure 22, when 

 its lid is removed. 



Figure 25 represents a plan of the four-pillar-slider - 

 holder, which is by far the best contrivance hitherto in- 

 vented, for attaching all sorts of objects in sliders and 

 between slips of glass, &c. to the stage : its elevation is 

 shewn at figure 26, with the two pins which secure it. 

 In the plan are drawn the two cross connecting bars, 

 'u, 'u, between which and the superior plate all large 

 opaque sliders, &c. are placed. There is another plate 

 below the first : between these two a common transpa- 

 rent slider is shewn. The helical spring is of steel of some 

 strength, so that the sliders shall not be permitted to 

 move about between the plates too easily. The holes at 

 the corners of the plates which slide up and down on the 

 pillars, must be sufficiently large to prevent any clinging 

 or sticking. 



Figure 28 shows a plan and profile of an adapter , 

 which carries a small aquatic live box, to be used with 



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