Chemistry and Physics. Pe? 
7. Relation between the Sun’s spots and the Earth's temperature. 
—At a meeting of the Physical Society in Berlin, Oct. 19, Dr 
any change in the temperature of the instrument 
used by Dr, Frolich consisted of a thermo-electric pile inclosed in 
a wide double walled pipe, opening in front in 
nel, in which circulated a constant stream of water at atmospheric 
pressure. The exposed front of the pile was closed by a plate of 
rock salt. The apparatus was capable of revolving in all direc- 
ions. his apparatus was preferred to Langley’s bolometer, 
since the electrical resistance of thin plates is subject to consider- 
able variation during long periods of time. As a standard of 
heat the author employed a hollow screen filled with steam, one 
side cat was blackened with smoke and the other whitened 
] 
sh 
. of the Dynamo-Electric machine.—CLAUvsivs enters. 
upon a theoretical discussion of this machine which is muc 
needed at tlie present time. The article is too long and mathe- 
matical for a suitable abstract. The question of the working of 
every machine as a magneto-electric engine first and afterwards, 
revolving core of the armature are also examined.—Ann. der 
——. und Chemie, 1883, No. 11, pp. 353-372. > a 
. 
‘ts poles opposite to that of the needles immediately below it. 
