THE Microscope. 51 
solid platform, any tremor or movement, caused by passing ve- 
hicles or other disturbances is communicated to object and image 
alike, producing a perfectly sharp negative. 
When the tube of the microscope is inserted inte the cone 
of the camera, the entrance of extraneous rays of light through 
the intervening space, is prevented, by wrapping a strip or sleeve 
of black cloth or velveteen, about the joint and securing same 
in position with a rubber band. With the bellows closed, all 
portions of both camera and microscope are brought into such 
close juxtaposition, that the manipulations of arranging,focusing, 
and illuminating the object, may be readily performed whilst 
the eye observes the image of the latter upon the focusing screen. 
But when it becomes necessary to extend the bellows, to increase 
the power, it will be found impossible for the hand to reach the 
various milled heads when the eye is in the necessary position 
for seeing the image upon the screen. If the image be properly 
centered with the bellows closed, it will remain so, even if they 
be extended to their utmost capacity ; but the focus will change, 
requiring the objective to be placed nearer to the object upon 
the stage with every inch that the bellows are lengthened. 
Some device whereby the fine adjustment may be controlled _ 
from the extreme back of the camera-frame becomes necessary. 
That which I have adopted possesses the merits of simplicity 
and effectiveness. A groove is turned in the periphery of the 
milled head controlling the fine adjustment, around which a 
cord is passed and carried through hook eyes on either side of 
the camera to the rear thereof. A couple of leaden weights at- 
tached to the ends of this cord serve to keep the same taut, 
whilst the slightest pull upon either, moves the adjusting screw 
with the utmost nicety. A fine fishing line isadmirably adapted 
to this purpose, the arrangement of which is clearly shown in 
the accompanying illustration. 
Any good kerosene or petroleum burning lamp may be used 
as the illuminating agent, if means are provided for maintaining 
the flame at the proper height for the optical centre of the mi- 
croscope. A German-student lamp is admirably adapted to this 
purpose as the flame may be raised to any desired position 
above the table, and fixed by means of a thumb screw. 
Fiddian’s Uluminator, (shown in the illustration, ) is also perfect 
