544 
POPULAR SCIENCE REVIEW. 
character of this description of enterprise very problematical ; 
and hence^ the hesitation of the public to subscribe the re- 
quired capital_, and the long delay in making a new experiment. 
Presuming that the readers of this journal will be suf- 
ficiently acquainted with the principles upon which tele- 
graphic communication, by means of electric currents, depends, 
it will be sufficient to state the pecuharities of the arrange- 
ments which have proved successful, and then proceed to the 
examination of the greater question of the Atlantic line. 
The Dover and Ostend cable was laid on the 6th of May, 1853. 
This cable (fig. 6, PI. XXI.) is 70 miles long; it is composed of 
six copper wires, insulated by a coating of gutta percha, which 
are essentially the electrical cable, and these are secured by an 
armour of twelve iron wires. The whole rope was capable of 
sustaining a strain of about 50 tons ; it weighed seven tons per 
mile, making a total weight of nearly 500 tons. It was made 
by Xewall & Co., in one hundred days, its cost being 
£33,000. It required seventy hours to coil it into the ship, 
and it was submerged in the sea, from Dover to Ostend, in 
eighteen hours. The arrangement of the inner wires did not 
prove entirely satisfactory. 
After the success in sinking the Dover and Ostend cable, 
Messrs. Xewall & Co. commenced laying a cable from Dona- 
ghadee, in Ireland, to Port Patrick, in Scotland, across the Irish 
Channel. This cable was of the same weight and size as fig. 6, 
but the conducting wires were differently arranged, as seen in 
fig. 7, PI. XXI. The drawings given are of the natural size. This 
cable was made in twenty-four days, and at a cost of £13,000. 
The Mediterranean cable ife of the same construction as that 
across the Irish Channel, and was laid in 1854. This line 
runs from Spezzia to the Island of Corsica. Over this there 
is a land line extending to the Straits of Bonifacio, where a 
short submarine line of seven miles runs to the Island of Sar- 
dinia. Across this island there is a line 203 miles long, 
terminating at Cape Spartivento. The telegraphic communi- 
cation between the Island of Sardinia and Africa seems to 
have been surrounded with great difficulties. Two attempts 
were unsuccessful, but the third (fig. II, PI. XXI.) proved, by 
its success, that perseverance accompanied by judgment usually 
attains the end desired. This cable, also made by Messrs. 
Xewall, was composed of four sets of conducting wires, and 
these, in the deep-sea portion, were protected by eighteen 
iron wires, while the shore end was surrounded by twelve 
much stouter wires. The shore cable was six miles in length. 
The distance between Cape Spartivento, in Sardinia, and 
Bona, on the African coast, is 125 miles. Messrs. Xewall & 
Co. also made the cable which unites Malta and Corfu with 
