AN INEXPENSIVE LAMP FOR ANALYTICAL BALANCE H. E. PHIPPS Eastern Illinois State Teachers College, Charleston, Illinois
ALL too frequently analytical balances are poorly illuminated for easy work, while the purchase of individual lamps is often too much of a financial drain when income is restricted. The following lamp is suggested as a t least a partial solution to the problem. It can be made in a relatively short time by anyone handy with tools. Tin plate (a large tin can will do) is cut, hemmed, and soldered together as shown in the drawing and photograph. The feet (2) have slots cut in them so that they may be slipped under the head of the wood screws which serve to fasten them securely to the balance case. These feet are fastened a t such a height (1) that the lamp bottom nearly touches the glass of the top balance window. Two holes (3) are drilled in the end opposite the receptacle for ventilation. A coat of aluminum paint inside and green or other color outside
The necessary materials, which may be obtained from anv dealer in electrical s u ~ ~ l i eand s . their cost are as follows: A.
Tin Plate, 7" X 10" X '/s' Keyed Receptacle PIUZ
s o . 04 0.20
n. n i ~~
~ n i ; t e a wire, 3 it Bulb (frosted tubular showcase) 25-watt Paint, about
Total
0.06 0.35 0.05
--
$0.75
improves the appearance and utility and also protects the lamp housing from corrosion. A 25-watt tubular Several of these lamps are being used in this laborafrosted bulb which is usedfor showcasesisrecommended, tory with very satisfactory results. hut an ordinary bulb may be used if the dimensions of I wish to express my thanks to Mr. Edsou Clodthe lamp housing are changed somewhat. However, felter, engineer, who made the lamps and assisted in dethe general illumination is not quite as satisfactory. signing them.
