'394 Q/ ^e Propagation of Heat 



rections, one above another, or regular WINDS, \vhich, 

 springing up in the different regions of this artificial 

 atmosphere, prevailed for a long time with the utmost 

 regularity, while the small particles of the amber col- 

 lecting themselves together formed clouds of the most 

 fantastic forms, which, being carried by the winds, ren- 

 dered the scene perfectly fascinating ! 



It would be impossible to describe the avidity with 

 which I gazed on these enchanting appearances. 



In the state of enthusiasm in which I then was, it really 

 seemed to me that Nature had for a moment drawn 

 back the veil with which she hides from mortal eyes her 

 most secret and most interesting operations, and that I 

 now saw the machinery at work by which winds and 

 storms are raised in the atmosphere ! 



Nothing seemed to be wanting to complete this be- 

 witching scene, and give it the air of perfect enchantment, 

 but that lightning, in miniature, should burst from these 

 little clouds ; and they were frequently so thickened up, 

 and had so much the appearance of preparing for a 

 storm, that had that event actually taken place, it could 

 hardly have increased my wonder and ecstasy. 



There were several accidental circumstances attending 

 this experiment which contributed to render it more in- 

 teresting. The sun, which happened to be remarkably 

 bright, shone full upon the window where the apparatus 

 was placed ; and as the grooves in the frame in which the 

 plates of glass were fixed were not deep, that part of this 

 frame which formed the narrow bottom of the box being 

 exposed to the sun's rays, a considerable quantity of 

 Heat was generated by them in that place, as appeared 

 by the motions of the particles of pulverized amber which 

 lay on the bottom of the box, or those which were 

 brought there by the currents. 



