X NOTES BY THE EDITOR 



that out of twelve thousand miles of submarine cable which have been 

 laid since 1851, only three thousand miles are actually in working or- 

 der ; so that three-fourths may be considered a failure and loss to the 

 country. The insulators hitherto employed are subject to deteriora- 

 tion from mechanical violence, from chemical decomposition or decay, 

 and from the absorption of water. But the last circumstance does not 

 appear to influence seriously the durability of cables. Electrically, 

 India-rubber possesses high advantages, and, next to it, Wray's com- 

 pound and pure gutta-percha far surpass the commercial gutta-percha 

 hitherto employed ; but it remains to be seen whether the mechanical 

 and commercial difficulties in the employment of these new materials 

 can be successfully overcome. The external protecting covering is 

 still a subject of anxious consideration. The objections to iron wire 

 are its weight and liability to corrosion. Hemp has been substituted, 

 but at present with no satisfactory result. All these difficulties, to- 

 gether with those connected with the coiling and paying out of the 

 cable, will no doubt yield to careful experiment, and the employment 

 of proper instruments in its construction, and its final deposit on the 

 bed of the ocean. 



" Irrespective of inland and international telegraphy, a new system 

 of communication has been introduced by Prof. Wheatstone, whereby 

 intercourse can be carried on between private families, public offices, 

 and the works of merchants and manufacturers. This application of 

 electric currents cannot be too highly appreciated, from its great effi- 

 ciency and comparatively small expense. To show to what an extent 

 this improvement has been carried, I may state that one thousand 

 wires, in a perfect state of insulation, may be formed into a rope not 

 exceeding; half an inch in diameter." 



O 



The Congress for the Promotion of Social Science, which has now 

 become an established institution in Great Britain, met, during the 

 past year, at Dublin, and was largely attended, some ninety-three 

 papers being read and discussed. Of these communications we note 

 the following, by title, as affording our American readers an idea of 

 the scope and objects of the Congress : 



" Suggestions on the Failure of Education in the Junior Classes of 

 Elementary Schools ; by the Rev. W. A. Willock, D.D." " On the 

 Application of the Principles of Education in Schools for the Lower 

 Classes of Society ; by Miss Carpenter." " A Scheme for the Adult 

 Education of the Working Classes ; by Mr. J. P. Organ." " Paper- 

 hangings Auxiliaries to Education ; by Mr. J. Stewart." " On the 

 Influence of Newspapers on Popular Education ; by Mr. G. W. Blan- 

 chard Jerrold." " On Art Education considered in its Utilitarian and 



