Intelligence and Miscellaneous Articles, 295 



then begins to be deflected in the opposite direction with a gradu- 

 ally increasing strength, until after a fresh flash a throw in the 

 opposite direction is observed. The intensity of the deflection 

 increases with the proximity of the lightning-flashes. — Beiblatter 

 der PhysiJc, vol. xi. p. 376 ; Electrotechnische Zeitschrift, vol. vii. 

 p. 445. 



ON THE MELTING-POINT OF ICE AT PRESSURES UNDER ONE 

 ATMOSPHERE. BY B. J. GOOSENS. 



The author finds that when the pressure is reduced from 760 to 

 5 millim. the melting-point of ice is raised 0*0066°. The determi- 

 nations were made as follows : — 



A glass tube was closed at the bottom by a cork, through 

 which thermoelements were inserted, so that one set of solder- 

 ings was inside and the other outside the tube. After the tube 

 had been filled with water, and placed in a vessel which also con- 

 tained distilled water, the upper end of the tube was connected 

 with the air-pump. The water in both vessels was then frozen, 

 and as the ice again began to melt, the whole apparatus was brought 

 into a large vessel containing lumps of ice. The ice in the interior 

 kept for several days. If some in the inner was melted all could 

 be frozen by lowering the pressure. A galvanometer was connected 

 with the thermoelements, and readings were made, firstly, when 

 there was the same pressure in both vessels ; and, secondly, after 

 the pressure in the inner vessel was lowered to 5 millim. ; and 

 after waiting until the temperatures were constant. — Arch. Neerland, 

 xx. p. 449. Beiblatter der Physik, No. 7, 1877. 



ON THE THOMSON EFFECT. BY A. BATELLI. 



The experiments were made with cadmium, which is relatively 

 homogeneous and shows the phenomenon in particular strength. 

 Two perfectly equal rods of pure cadmium 36 centim. in length, 

 and 5 millim. in thickness, were covered in the middle and at each 

 end for a length of 5 millim. with copal varnish, which resists tem- 

 peratures over 200°, and does not transmit mercury, and were 

 wound with a very thin silk ribbon. The two bars passed through 

 two perfectly similar boxes of sheet-iron filled with equal quantities 

 of mercury, in which were immersed the middles of the rods. 

 Where each end projected from the box thermoelements of thin 

 iron and argentan wires were fastened to the rods. The varnished 

 ends of the rods were in melting ice, and the unvarnished in a 

 steam bath, and were connected there by a thick copper wire. 

 The cold ends were connected with the poles of a battery of 2 Bun- 

 sen's elements. In the mercury in the two iron boxes (which 

 was kept in motion by a stirrer) dipped the two varnished junc- 

 tions of a thermopile of two iron-argentan elements connected 



