. 
608 NEW MICRO-TELESCOPE. 
country will freely coöperate with microscopists attaining this very de- 
sirable result. The introduction already T accomplished, o of a grad- 
ing of the pcs =i comparison with equiv se ara pi lenses, 2in., 1 
in., etc., may render this Lava of the subject, ich seemed almost. 
unattainable, ‘the cere and fi to be Senne ed. The remarks on 
the subject of powers will be ace in a future number of the NaTURALIST. 
On a New Micro-recescore. —By Pror. R. H. Warp. 
Tus is designed especially for travelling and field use, but ap- 
plicable to some of the daily work of the microscopist. It con- 
sists of a stand and accessories as follows: (A) An ordinary Tank 
Microscope having the body focussed by a rack and clamped at 
any desired height upon a stand like that of the bull’s eye con- 
densers. Probably few naturalists have any suspicion of the real 
usefulness of this little piece of apparatus, not only in the study 
of objects living in an aquarium or preserved in alcohol, glyce- 
rine, etc., but for the hasty inspection of herbarium specimens 
permanently fastened upon sheets of paper too large for the stage 
of an ordinary microscope, and for the preliminary examination of 
objects in jars, boxes, dissecting troughs, etc. The writer always 
keeps upon his working table such an instrument carrying a double 
nose-piece (the crooked form) and usually one-inch and three-inch 
objectives, and uses it continually and with great satisfaction as 
a substitute for a simple microscope. The brass foot-plate at 
the bottom of the upright pillar should be made somewhat larger 
and heavier than usual. (B) A Stage of convenient size and 
simple construction, sliding upon the upright pillar and capable of 
being clamped securely in any position. This stage carries 4 
diaphragm and mirror below and stage forceps above, and enables 
the instrument to be used as a vertical compound microscope for 
ordinary work when, as in travelling or on a field-day, no more 
commodious stand may be available. This combination may also 
be used as a dissecting microscope, though for that purpose it is 
greatly preferable to use the Tank Microscope as a magnifier only, 
and to place the object, if opake, on the table, or if transparent, 
on the stage of any good dissecting microscope that may be within 
reach. (C) A Draw Tube sliding over the compound body from 
below, and capable of being fastened by a bayonet catch to the 
brass-work through which the compound body is moved by the 
rack. The objective in the compound body now acts as an erec- 
tor, and another is to be screwed, by means of a large adapter, 
into the lower end of the Draw Tube, to act as the objective. 
