QF MICROSCOPIC OBJECTS. 51 
make a hemispherical cavity to fit half of the ball, and bore 
a hole through from the middle of this cavity, to allow the 
wire to pass. Take another piece of board, about four inches 
in diameter, either round or square, and one and a half or 
two inches thick, make a similar cavity in its centre to 
receive the other half of the ball, but only so deep as to — 
allow the ball to fit tightly when the two pieces of board . 
are screwed together, which last operation must be done with 
three or four screws. Let the hole for the wire in the upper 
part be made conical (base upwards), and so large as only 
to prevent the ball from escaping from its socket, in order 
that the shaft may move about as freely as possible. Turn 
a cavity, or make holes, in the bottom of the under piece, 
and fill with lead to give weight and steadiness. This, 
painted green bronze and varnished, looks neat; and by 
having pieces of gutta-percha tubing to fit the shaft, a great 
variety of apparatus may be attached to it. 
Mr. Loy employs the following arrangement for dissecting 
insects or picking out Foraminifera, &c.: he fits an upright 
brass rod into a heavy leaden foot, this rod carries a hori- 
zontal arm bearing at its end a ring for holding a watch- 
maker’s eye-glass; in focussing it to his work, he presses 
the eye-glass down with his head, the weight of the leaden 
foot keeping it in its place, and allowing it to follow his 
every movement, 
Again, a “ condenser ” is often required for the illumina- 
tion of opaque objects. My ingenious friend uses an 
“engraver’s bottle” (price 6d.), fills it with water, and 
suspends it betwixt the light and the object. Where the 
light is very yellow, he tints the water with indigo, and so 
removes the objectionable colour. 
I merely mention these as examples of what may be 
done by a little thoughtful contrivance, and to remove the 
idea that nothing is of much value save that which is the 
work of professional workmen, and consequently expensive. 
