118 ANNUAL OF SCIENTIFIC DISCOVERY. 



which ceased, however, when they took the precaution not to touch the 

 wires with naked hands. These spasms were most frequent and in- 

 tense in the highest region of the line. The action of atmospheric 

 electricity on the telegraphs is stronger on the approach of a storm. 



ATMOSPHERIC ELECTRICITY. 



THE council of the British Association, in their report, observe, that 

 among the results obtained by the observations upon atmospheric elec- 

 tricity at Kew, are these. During the twenty-four hours, the electri- 

 cal tension of the atmosphere acquires two maxima, about 1 A. M. and 

 10 P. M., and suffers two minima, about 4A.M. and 4 P. M., these 

 being also nearly the hours of barometrical maxima and minima. In 

 the course of the twelve months there is distinctly a periodicity of elec- 

 trical tension ; the maximum for the year being in the depth of winter, 

 and the minimum in the height of summer. London Atkenesum, 

 August, 



In the course of a paper on the " electricity of the air," Mr. Fara- 

 day states the following as the results obtained by M. Quetelet, of 

 Brussels, from observations on atmospheric electricity. 1. Its quan- 

 tity increases directly with the distance from the earth's surface. 

 2. The electricity is greatest in the coldest months. 3. It is greatest 

 at 8 o'clock A. M., and 9 P. M. 4. It is always greatest when the 

 sky is clear. 5. The electricity of fog or snow is double that of rain, 

 and equal to the mean maximum of the cold months. 6. During five 

 years but twenty-five instances of the atmosphere being in the negative 

 state have been noticed, and these were either directly before or after 

 rain cr a storm. 7. The electricity is greatest in quantity when the 

 wind is from S. E. to E. S. E. and from W. N. W. to N. W. ; the in- 

 terposed minima were at W. S. W. to W., and at N. to N. N. W. 



IMPROVEMENTS IN TELEGRAPHS. 



FROM the large number of improved telegraphs produced during the 

 past year we have selected the following, as apparently the mostVor- 

 thy of notice. 



Electro-chemical Telegraph. Messrs. Westbrook and Rogers, of 

 Baltimore, have received a patent for an improvement in electro-chem- 

 ical telegraphs, the claim for which is as follows : " What we claim 

 is, recording telegraphic signs on the surface of a revolving metallic 

 cylinder, plate, or other equivalent surface, by means of an acidulated 

 liquid, or saline solution, or water, held between the point of the wire 

 conductor and the metallic surface, by means of a non-conducting po- 

 rous substance, contained in a glass or other non-conducting reservoir, 

 in which the recording fluid is contained, to which the electric current 

 from a battery is applied by means of any of the known forms of ma- 

 nipulators and anvils used for making and breaking the circuit ; the 

 recording fluid being applied to the metallic recording surface, substan- 

 tially in the manner herein set forth, by which the use of every de- 

 scription of paper is dispensed with, thereby saving great expense in 



