STATE PLANT BOARD
United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant Quarantine
By Francis Munger.
Division of Fruit Insect Investigations
Shortages of critical materials have limited the supply of
factory-made laboratory equipment. A lamp constructed largely from
materials already on hand in the laboratory is here described for the
information of other workers who may be faced with a similar need. The
lamp assembly consists of a wooden stand made to support a box holding
a straight-sided glass Jug containing distilled water. The electric-
light bulb is so placed that the light shines through the jug, producing
a working light that is bright, diffused, and cold.
The following materials are required:
(1) 150-watt, 110-volt, "reflector-spot" bulb'/ with socket.
(2) Rectangular glass Jug, 1-gallon capacity.
(3) Two carriage bolts, 1/4 by 2 inches, with wing nuts
and several screws; strip metal and small bolts
for the socket clamp.
(4) Lumber as needed for base, uprights, and box:
One wooden base, 6 by 9 1/4 by 3/4 inches.
Two wooden uprights, 3 1/2 by 18 by 3/4 inches.
Other lumber for construction of box.
The assembly of the parts is shown in figure 1.
The stand is made by fastening the two uprights to the top side of
the base, with long screws. The uprights are slotted to accommodate
bolts which hold the box for the glass jug. The bolts and the slots
make it possible-to adjust the elevation and angle of the light. The
bottom and two sides of the box are made of 1/2-inch wood. One side is
left open, and the side opposite is covered with a piece of 1/4-inch
Dlywood. A hole 5 inches in diameter is cut in the plywood to allow
the light to shine through. Two strips of metal are attached to the
box to hold a clamp for the light socket.
A smaller field of light can be obtained by inserting a cardboard
shield with a smaller hole between the Jug and the plywood. If a blue
tint in the light is desired, some copper sulfate can be dissolved in
_/ There are at least two brands of these bulbs on the market.
Its essential feature is a built-in parabolic reflector, which produces
an intense beam of light.
UNIVERSITY OF FLORIDA
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Yigare 1.-Microsecope lap assembly. (Drawing made by
F. S. Stickneo) The upright on the left has been
out down to show details.