Physics. ; 225 
‘it to keep any loose silver from dropping on the cathode. The 
anode is immersed in the solution of silver salt; and at the end 
is made by weighing the bowl cathode in a chemical balance. 
This process is i preferable to Nebel ihe the loss of wens 
of the ee —Nature, July 17, 1884, p. 2 
. Change of temperature due to ‘Pijashaten and Pais 
cypaarbaaen Soir Ba chmetieff has made at the est ahe ti of Zurich 
‘a. “Beasties a8 a Swan incandescent lamp at different tem- 
peratures—H. Schneebeli employed in toe. saci wy the 
method of Svehie and Langley. The resistance of the lamp 
while cold was 80 ohms. The following tables exhibit the results : 
No. 1. No. 2. 
Current Entire Light radiation | Current Entire Light radiation 
Strength. radiation. in candles. strength. radiation. in candles. 
44°5 87-0 sk 480 102°0 03 
-48°8 97-0 0°25 76°2 0 55 
57-0 158° 0-70 94:2 392-0 24-0 
67-0 195- 1°85 
75-0 250: 5 
88°2 348° 17°5 
For each i strength, J, there exists the following relation, 
J*°W=CS, in which W is t the t esistance of the carbon at the des- 
ignated cecapetatnens S the energy emitted by the lamp, and C is 
a constant. If W, the enlaces of the lamp, is constant Citivas 
900° and 1500° temperature, one has J = constant. This is 
expressed by the following values: 
Je 446, 488. BT 67. 160. 882. 480 76 94°2 
gS 28 46 207 230 225 (84 B86 6228 226 
The resistance of carbon between red heat and white heat appears 
to be independent of temperature. The absorption coefficient of 
the glass globes of the lamp appears also to be independent of the 
temperature between —— limits.— Ann. der Physik und Chemie, 
No. 7 7, 1884, pp. 430 T. 
7. gE ho le Bzhibition at Philadelphia. ili Electrical 
Exhibition which the Franklin Institute is making extensive pre- 
Parations to hold in Philadelphia, during the months of September 
and October of the. pe year, promises to be a large and 
