NATURAL PHILOSOPHY. 



145 



tiona of different distances recorded themselves upon the same slip of paper, 

 thus, O'SS and 249 miles were imprinted upon one paper, 0'83, 498 miles 

 upon another slip, 0'249, 498 upon another, and 0-535, 1,020 upon another. 

 Thus, by the juxtaposition of the several simultaneous records on each slip, 

 as well as by the comparison of one slip with another, the author has been 

 enabled to show most convincingly that the law of the squares is not the law 

 which governs the transmission of signals in submarine circuits. Mr. White- 

 house showed next, by reference to published experiments of Faraday's and 

 "VYheatstone's (Philosophical Magazine, July, 1855), that the effect of the iron 

 covering with which the cable was surrounded was, electrically speaking, 

 identical with that which would have resulted from submerging the wire, and 

 that the results of the experiments could not on that point be deemed other- 

 wise than reliable. The author then addressed himself to the objections 

 raised against conclusions drawn from experiments in " Multiple" cables. 

 Faraday had experimented, he said, upon wires laid in close juxtaposition, 

 and with reliable results ; but an appeal was made to direct experiment, and 

 the amount of induction from wire to wire was weighed, and proved to be as 

 one to ten thousand, and it was found impossible to vary the amount of 

 retardation by any variation in the arrangement of the wires. Testimony, 

 also, on this point was not wanting. The Director of the Black Sea Tele- 

 graph, Col. Biddulph, was in England, and present at many of the experi- 

 ments. He confirmed our author's view, adding, li that there was quite as 

 much induction and embarrassment of instruments hi this cable as he had 

 met with in the Black Sea line." The author considers it. therefore, proved 

 "that experiments upon such a cable, fairly and cautiously conducted, may 

 be regarded as real practical tests, and the results obtained as a fair sample 

 of what will ultimately be found to hold good practically in lines laid out in 

 extenso. At the head of each column in the annexed table is stated the 

 number of observations upon which the result given was computed, every 

 observation being rejected on which there could fall a suspicion of careless- 

 ness, inaccuracy, or uncertainty as to the precise conditions ; and, on the 

 other hand, every one which was retained being carefully measured to the 

 hundredth part of a second. This table is subject to correction, for variation 

 in the state of the battery employed, just as the barometrical observations 

 are subject to correction for temperature. 



Amount of Retardation observed at various Distances. 



stated in Parts of a Second. 



Voltaic Current. Time 



Now it needs no long examination of this table to find that we have the 

 retardation following an increasing ratio. that increase being very little be- 



7 



