480 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



mann placed two vessels of mercury in a glass trough filled 

 with acidulated water, and with pistons, composed of capil- 

 lary tubes filled with mercury, inserted into the vessels of 

 mercury ; the alternate contraction and expansion of the 

 mercury in the pistons, as they are connected with one or 

 the other pole of a galvanic battery, furnishing the motive 

 power in the case. 14 (7, CCXIL, 300. 



SCIENTIFIC BALLOON ASCENSION. 



A balloon ascension made on the 2d of November, 1873, at 

 Charkow, in Russia, by Bunelle, is worthy of special mention. 

 In 8-J hours the balloon traveled 190 kilometers, going al- 

 ways in the same direction toward the N.N.E. The great- 

 est altitude was about nine thousand feet ; and the small 

 quantity (thirty-five pounds) of ballast used shows how well 

 the aeronaut managed the length of his voyage. The move- 

 ment of the lower strata of air was always greater than that 

 of the upper strata. At an altitude of three thousand feet 

 the hourly velocity was twenty-one miles, while in the im- 

 mediate neighborhood of the earth the force of the wind was 

 so great that Bunelle could with difficulty effect a landing. 

 The shadow of the balloon on the earth was a very well-de- 

 fined black spot, whose movement across the country gave, 

 by means of an accurate map, the means of determining the 

 velocity of the current of air. At sunset a heavy rain-fall 

 was experienced in the interior of the clouds. Above the 

 clouds the aeronaut found a beautiful sky and a very pleas- 

 ant temperature. The condition of the atmosphere appears 

 to have been directly the opposite of that experienced by 

 Glaisher on July 11th, 1863. The latter found himself in a 

 northerly current, which was warmer the nearer he approach- 

 ed the earth. Heis, Wbc/mischrift, 1874, 154. 



eussian versus welsh coals. 



Chief-Engineer Isherwood, of the United States Navy, in a 

 report on the investigation of the value of Russian coal from 

 the basin of the River Don, states that the deposits of this 

 coal, which are now being mined, are immense. Some of it 

 has an exceptional purity, yielding only two or three per 

 cent, of ash. The calorific effect has been carefully investi- 

 gated, the result being to disprove the reliability of the law 



