TRANSACTIONS. 
Description of a new Stand for a Single Microscope^ with 
an arrangement for using the magnifiers ivith both eyes. 
By Richard Beck. 
(Read Oct. 14tli, 1863.) 
The base of this instrument is a square block of mahogany 
(Figs. I and II), with the top edge and corners rounded off, and 
at the angles are four strong brass pillars, which support, 
at a height of four inches from the table, a brass plate 
six and a half inches square ; above this are two circular brass 
plates : the first is the same diameter as the square plate, 
with a revolving fitting at the centre, and the means of 
tightening it down underneath by a large milled head ; 
the second and top plate of all is much smaller, and is 
held down by springs, which allow it to be moved pleasantly 
over the lower plate to the extent of three quarters of an inch 
in any direction ; this is equivalent to a space at the centre of 
one and a half inches diameter, and of this size the opening 
of the top stage is made for the reception of various glasses, 
troughs, or holders for dissection. 
The magnifiers drop into the extremity of an arm, 
which comes in a diagonal direction from the left-hand back 
pillar ; here it is fixed to a triangular bar, which can be moved 
up or down by a milled head, connected with rack and 
pinion for adjustment of focus ; the arm can be turned on one 
side to the left, but in the other direction it stops, when cen- 
tral with the revolving fitting of the first circular brass plate 
already alluded to. 
When light is required from below for transparent objects, 
a concave mirror, provided with a semicircle and other 
necessary fittings, can be turned up from a recess in the ma- 
hogany base, and a side condensing lens, with ball and 
socket and other movements, supplies all necessary illumi- 
nation from above. 
VOL. XII. a 
