120 ANNUAL OF SCIENTIFIC DISCOVERY. 



sive force of the caloric. M. Andrand has not put this idea into prac- 

 tice ; but in the course of his trials he has several times remarked an 

 unexpected fact which we here mention. 



Before making his air locomotive public, M. Andrand had it in ope- 

 ration within his workshop. When the reservoir was well filled with 

 condensed air, the fire of the dilatator was made, and the iron plates 

 of the bottom of the cylinders were brought to a white heat. This 

 done it was only necessary to open the stop cock of the reservoir to 

 set the machine in motion, and cause the two driving wheels to re- 

 volve. But while the apparatus was heating up, and before the valve 

 was opened, it happened several times that the machine started spon- 

 taneously and communicated to the two wheels a frightful velocity. The 

 phenomena continued from 30 to 40 seconds, then ceased, without 

 his discovering how it was produced, or why it stopped. M. Andrand 

 has not succeeded in repeating it at will. Already, some three years 

 previous, the same motion, spontaneous and violent, manifested itself 

 two or three times in a small hot-air car, which this mechanician had 

 made to move on rails. 



What may be the cause of this singular phenomena ? Those who 

 explain everything by a word, who know the precise cause of the 

 cholera, steam-boat explosions, the potato disease, &c., do not fail to re- 

 ply that the cause is " electricity," and without looking much to the 

 why, or the wherefore, they can easily solve many other difficult prob- 

 lems the same way. M. Andrand, who has as a mechanician, a well- 

 merited reputation, does not hesitate to assign the same cause ; and 

 his explanation is not without a shadow of foundation. The two mo- 

 tor cylinders, which act independently on the driving wheels, are of 

 different kinds, one wholly of bronze, the other, by chance partly of 

 cast-iron, and partly of bronze. But the phenomena does not appear 

 to be produced in this last cylinder, and never in the cylinder of one 

 metal. The two cylinders of the locomotive, in which the spontaneous 

 movement was reproduced, also consisted of two metals, the cylinders 

 being of cast-iron, and the pistons and bottom of bronze. From this 

 to the phenomena of Galvani, is but a single step ; and M. Andrand is 

 convinced that he has been witness of the mechanical work of the 

 electricity excited by the heat. Setting aside an explanation which 

 elucidates nothing, and which may mischievously make one believe 

 that the problem is resolved when it is hardly presented, we may con- 

 clude with M. Andrand, who says : It will be a conquest, both scien- 

 tific and industrial of the first order, when we shall succeed in produc- 

 ing at will, this new motive force, and give it a continued action ; then 

 two ordinary motor cylinders, moderately heated and fed successively 

 with a very small quantity of air, will suffice to generate an enormous 

 force, which M. Andrand estimates at 10 or 12 atmospheres, and this 

 with an expense of heat altogether insignificant. We shall have then, 

 says he, electro-caloric engines which shall leave far behind steam-en- 

 gines, however perfect, and shall realize under volumes of small ex- 

 tents, the marvels attributed to the apparatus of Ericsson. 



Finally, M. Andrand closes his memoir by the following consul- 



