Chronometers. 297 



when the wind blows from the north west. I have observed, at 

 such times, the hairs of the horses tails so charged, that whole bunch- 

 es would adhere with considerable force to the horses flanks, or, at 

 other times, the individual hairs, repelled by their neighbors, would 

 stand several inches apart. Distinct shocks, may then be obtained 

 in the fingers, by rubbing the back of a cat with one hand, and hold- 

 ing the point of its tail firmly with the other. One day, last winter, 

 I observed a silk apron attracted by the table so strongly, and at 

 such a distance from it as to enable the wearer to keep it suspended 

 in the air, at a full right angle. When silk or flannel, is removed 

 rapidly from the body in the dark, it will exhibit for the moment, 

 one luminous electric sheet, and a distinct crackling noise may be 

 heard. Besides these facts, many very interesting electrical phe- 

 nomena may be observed. 



Should this prove interesting, I should take pleasure in furnishing 

 regularly meteorological observations. If I do, I shall take every 

 pains to procure instruments of unquestionable accuracy. 

 New Harmony, Indiana, May 28th, 1835. 



Art. XVIII. — Chronometers. Communicated for insertion in 

 this Journal, in a letter to the Editor, dated London, Sept. 8, 

 1835. 



4, Change Alley, May 15, 1834. 



TO CAPT. SIR JOHN ROSS, R. N ., &C. &C. &C. 



Sir — In compliance with your desire to be furnished with a report 

 of the condition of the two chronometers of our make, which you 

 took with you in your late expedition to the Arctic Regions, we have 

 examined them with the most careful and minute attention, and find 

 them in an excellent state : indeed, very far more perfect than could 

 have been expected, after such a length of time, and the severe tri- 

 als which they must have undergone. 



With regard to their peculiar construction, which you at the same 

 time requested us to describe, as you were desirous of publishing it 

 for the benefit of science and navigation generally, we have no hesi- 

 tation in complying with your wishes ; and we do so the more readi- 

 ly, in the hope that our communication may prove useful. 



The peculiar principle which we have discovered is of the highest 

 importance in giving the final adjustment to chronometers, as by it 



Vol. XXIX.— No. 2. 38 



