NATURAL PHILOSOPHY. 227 



M. Olioli, a very learned Italian, brought before the Scientific Congress at 

 Iviplcs the following four cases of impressions made by lightning. In Sep- 

 tember, 1825, lightning struck the foremast of the brigantine St. Buon Circo, 

 in the bay of Arniro ; a sailor sitting under the mast was struck dead, and 

 on his back was found an impression of a horseshoe, similar even in size to 

 that fixed at the mast head. On another occasion, a sailor standing in a 

 similar position, hud on the left of his breast the impression of a number 

 44, with a dot between the two figures, being in all respects the same as a 

 number 44 that was at the extremity of one of the masts. On the 9th of 

 October, 133G, a young man was found struck by lightning. He had on a 

 girdle, with some gold coins in it; these were imprinted on his skin in the 

 same manner they were placed in the girdle; thus a series of circles with one 

 point of contact was plainly visible. The fourth case happened in 1847. 

 Mrs. Morosa, an Italian lady of Lugano, was sitting near a window during 

 a thunder-storm, and perceived the commotion, but felt no injury ; but a 

 flower which happened to be in the path of the electric current was perfectly 

 re-produced on her leg, and there it remained permanently. M. Poey also 

 mentions the following instance, which came under his personal observation 

 in Cuba : On the 24th of July, 1852, a poplar tree in a coffee plantation 

 being struck by lightning, on one of the large dry leaves was found an ex- 

 act representation of some pine trees that lay at the distance of 339 metres 

 (three hundred and sixty-seven yards, nine inches). As to the theoretical 

 explanation of lightning impressions, Mr. Poey thinks that they are produced 

 in the same manner as the electric images obtained by Moser, Eiess, Karster, 

 Grove, Fox Talbot, and others, either by statical or dynamical electricity of 

 different intensities. The fact that impressions are made through garments 

 is easily accounted for when we remember that their rough texture does not 

 prevent the lightning passing through them, with the impression it has re- 

 ceived. To corroborate this view, Mr. Poey mentioned an instance of light- 

 ning falling down a chimney, and passing into a trunk, in which was found 

 an inch depth of soot, which must have passed through the wood itself. 



PHOTOGRAPHS OF THE FIXED STARS. 



At a recent meeting of the American Academy, Boston, Mr. G. P. Bond 

 communicated the results of an examination of the photographs of the star 

 Mizar (^ Ursa Majoris, with its companion, and the neighboring star Alcor ;) 

 specimens of which were exhibited. 



Daguerreotype images of the star Yega, (a Lyra?) were obtained at the 

 Observatory of Harvard College by the well known artist, Mr. J. A. "Whipple 

 of Boston, on the 17th of July, 1850, and subsequently impressions were 

 taken from the double star, Castor, exhibiting an elongated disc, but no dis- 

 tinct separation of its two components. These were the first, and, till very 

 recently, the only known instances, of the application of photography to the 

 delineation of the fixed stars. 



A serious difficulty was interposed to farther progress by the want of suit- 

 able apparatus for communicating uniform sidereal motion to the telescope. 



