414 ANNUAL OF SCIENTIFIC DISCOVERY. 



their capabilities of affording material for evaporating; and it is precisely 

 what should occur, if one were fluid and the other almost entirely solid mat- 

 ter. On approaching the sun, the nebulous appendage of the first would 

 swell by the introduction of vapor; while the small amount of vapor con- 

 tained in the other would be only rendered invisible by the solar heat. 

 Other comets present indications of similar commotions, though, not at- 

 tended with such remarkable results; and we thus become acquainted with 

 the relation between the agencies operating on our globe and in the more 

 humble members of the solar family. 



NEW PERIODICAL COMET. 



The comet discovered by Mr. Tuttle, of Cambridge, on the 4th of January, 

 18-18, has been found to possess elements identical with those of the second 

 comet of 1790, discovered by Me'chain. Mr. Brahns, of Berlin, who discov- 

 ered this comet seven days after Mr. Tuttle, has compared a great number 

 of observations, made up to the month of March, in Europe and America, 

 and has deduced from them an elliptical orbit of 13 "GO years. The comet 

 discovered on the 4th of January by Mr. Tuttle has therefore returned four 

 times since 1790 without having been seen. 



ON THE GREAT AURORAL DISPLAY OF AUGUST 28TH TO SEPT. 



4TH, 1859. 



On the evening of August 28th, 1859, was commenced an exhibition of 

 Auroral or Polar light, which continued with varying intensity at different 

 localities in North America, so far as is now known, up to September 4th. 

 This auroral display Avas one of the most remarkable ever recorded in the 

 United States, remarkable not only for the great extent of territory over 

 which it was observed, but also for its duration, for the intensity of the illumi- 

 nation, as well as the brilliancy of the colors, and the extreme rapidity of the 

 changes. It was also equally remarkable for the magnetic disturbances which 

 accompanied it, especially on the 2d and 3d of September. These electrical 

 perturbations were recorded not only by the usual magnetic instruments; 

 but over the whole system of telegraphic wires, especially in Xew England 

 and the Canadas, the magnetic induction either greatly interfered with or 

 prevented the working of the lines by the usual voltaic current, while in 

 more than one case the north and south lines were worked solely by the 

 atmospheric influence ! Silliman's Journal. 



In some instances, lines were worked constantly for two hours in this way, 

 the currents being variable, but always sufficient for the purpose. These 

 phenomena had been previously noticed to some* extent, and the telegraph 

 operators were fortunately sufficiently well informed on the subject to ob- 

 serve and experiment intelligently. The following reported conversation 

 over the wires between Boston and Portland, on the evening of Sept. 3d, will 

 give an idea of the way in which they managed it : 



Boston (to Portland operator). "Please cut off your batteiy entirely 

 from the line for fifteen minutes/' 



Portland. " Will do so. It is now disconnected." 



Boston. " Mine is also disconnected, and we are working with the auroral 

 current. How do you receive my writing? " 



Portland. "Better than with our batteries on. Current comes and goes 

 gradually." 



