152 ANNUAL OF SCIENTIFIC DISCOVERY. 



iment was the same, as was, also, the Aurora Australia^ in the Antarctic re- 

 gions, where no colored icebergs were ever seen. At the time this theory was 

 first promulgated a controversy took place between the celebrated Prof. Schu- 

 macher, of Altona, who supported my theory, and the no less distinguished M. 

 Arago, who, having opposed it, sent M. G. Martens and another to Hammer- 

 fest on purpose to observe the aurora, and decide the question. I saw them 

 at Stockholm on their return, when they told me their observations tended to 

 confirm my theory ; but their report being unfavorable to the expectations of 

 M. Arago, it was never published ; neither was the correspondence between 

 the two Professors, owing to the lamented death of Prof. Schumacher. I re- 

 gret that it is out of my power to exhibit the experiments I have described, 

 owing to the peculiar manner in which the room must be darkened, even if I 

 had the necessary apparatus with me ; but it is an experiment so simple that 

 it can easily be accomplished by any person interested in the beautiful pheno- 

 mena of the Aurora Borealis." 



A GALVANIC ACTION IN THE EARTH. 



An eminent London cutler (Mr. Weiss of the Strand), to whose inventions 

 modern surgery is under considerable obligations, has remarked that steel 

 seemed to be much improved when it had become rusty in the earth, and pro- 

 vided the rust was not factitiously produced by the application of acids. He 

 accordingly buried some razor-blades for nearly three years, and the result 

 fully corresponded to his expectation. The blades were coated with rust, 

 which had the appearance of having exuded from within, but were not eroded, 

 and the quality of the steel was decidedly improved. Analogy led to the con- 

 clusion that the same might hold good with respect to iron, under similar 

 circumstances ; so, with perfect confidence in the justness of his views, he 

 purchased as soon as an opportunity offered, all the iron, amounting to fifteen 

 tons, with which the piles of London Bridge had been shod. Each shoe con- 

 sisted of a small inverted pyramid, with four straps, rising from the four sides 

 of its base, which embraced and were nailed to the pile ; the total length, from 

 the point which entered the ground, to the end of the strap, being about sixteen 

 inches, and the weight about eight pounds. 



The pyramidal extremities of the shoes were found to be not much corroded, 

 nor, indeed, were the straps ; but the latter had become extremely and beauti- 

 fully sonorous. When manufactured, the solid points in question were con- 

 vertible only into very inferior steel ; the same held good with respect to such 

 bolts, and other parts of the iron-work as were subjected to the experiment, 

 except the straps : these, which, in addition to their sonorousness, possessed a 

 degree of toughness quite unapproached by common iron, and which were, in 

 fact, imperfect carburets, produced steel of a quality infinitely superior to any 

 which, in the course of his business, Mr. Weiss had ever before met with ; in- 

 somuch, that while it was in general request among the workmen for tools, they 

 demanded higher wages for working it. These straps, weighing altogether about 

 eight tons, were consequently separated from the solid points, and these last 

 sold as old iron. The exterior difference between the parts of the same shoe, 



