2 BecKj on a New Stand for a Single Microscope. 
In most dissecting microscopes the magnifier is moved over 
the object; and consequently away from either condenser or 
riG. I. 
mirror illumination. In this instrument the magnifying'power 
is stationary^ and not only does the illumination remain the 
same whilst the object is moved about in every direction^ but 
any particular part that is being examined will remain in 
view whilst it is rotated by turning the large circular brass 
plate. 
The following are the advantages of this construction : — The 
size_, or as it might be termed spread of the microscope^ gives 
great firmness_, and also allows plenty of room on the top 
plates for the hands to rest upon during dissection. 
The stand is comparatively low; for, in a single microscope 
it is necessary to allow some considerable open space beneath 
the lowest part of the stage, to admit of an illumination from 
below when the light in front is at a moderate elevation ; but 
this unavoidable height is taken full advantage of by giving a 
range of three inches and six tenths to the rack of the trian- 
gular bar, and thus an object of considerable thickness may be 
placed on the instrument. 
The different dissecting instruments and appliances to the 
stage are a selection from those recommended by various 
naturalists, and require no particular description ; neither is 
there much to say respecting the magnifiers, which are either 
single lenses or Coddingtons, excepting a pair of achromatic 
powers, which may be used either separately or in combina- 
