LANKESTER, ON A MUSEUM MICROSCOPE. 207 
screw, which is attached to the holder, i, and which occupies 
the place of the stage. By this means eight, ten, or more 
objects may be mounted at the same time, and brought 
under the object-glass by merely moving the circular slide. 
The compound slide for viewing opaque objects (fig. 2 f) 
is constructed on a somewhat different plan. It is a frame 
into which the common glass slides, three inches by one, can 
be pushed, and when it is filled up they are secured by means 
of the screws, &. . The slides in their frame are then made 
to move backwards and forwards in a frame attached to the 
arm, 7, which is situated in the place of the ordinary stage. 





Fig. 2. 
Although this slide was made for mounting opaque objects 
upon the upright stand, it can be equally applied to trans- 
parent objects and the oblique stand. 
Two of these microscopes, constructed by Mr. Ladd, 
of Chancery Lane, have been at work for some weeks 
in the Food collection of the South Kensington Museum, 
and have excited great interest amongst those who have 
visited the Museum. A list of the objects exhibited, as 
numbered on the slides, is placed on the table, and 
every one seeing the object can thus obtain some know- 
