-< II KXIIIHITIOX. 



SS9 



lie; in>lriiments \vliich tran- 



M\VII handwriting. The iii-tniments 



in Knglawl niv the needle and 



tin- tir-' "ignals by 



traiiMea: ami ar!>itrary UK-. .ds, its 



- dependent solely ii|iiui tin- (.'. 

 tii. n of a quick-eyed or sharp-cared clerk; the 

 I recording its- arbitrary dashes and dots 

 upn |>a|ierin a permanent mauiier, more easily 

 .did tlieret'ore moiv accurate in its working. 

 The needle in-t ruincitts, c >(' which t he re are sev- 

 eral kinds in use, but none exhibited in Paris, 

 are very simple in their const ruction, easily reg- 

 ulated, and very constant and accurate in their 

 action. Their threat merit is, that any number 

 of stations can bo inserted intermediately, with- 

 out breaking the circuit or interfering with the 

 general working. Thus they are peculiarly 

 applicable tor railway purposes, and it is no 

 unusual thing to find twenty stations all in 

 minication with each other by means of 

 only one wire. The Morse instrument, which 

 has received so many brilliant touches from 

 the hands of the unrivalled instrument-ma- 

 kers of Paris, is almost exclusively used by the 

 Electric Telegraph Company for commercial 

 purposes. The replacement of the old Amer- 

 ican form of embossing by the new method of 

 inking was a great improvement. 



Mr. Ciilley gives the following as the highest 

 speed on a circuit of a little under 200 miles: 



Double needle, 35 words per minute. 

 Printing (Morse), 38 words " 



The average of two or three hours' continuous 

 work, reporting a speech of Bright's : 



Double needle. 24.3 words per minute. 

 Printing, 26.5 " " 



The other instruments used in England are 

 Ilughes's printing, employed by the United 

 Kingdom Telegraph Company, Wheatstone's 

 and Siemens's alphabetical-dial instrument, and 

 Bright's ficoii.-tiii telegraph. 



In France they use generally Morse's for 

 commercial purposes, but it is being much re- 

 placed by Ilughes's; and they also employ 

 Breguct's dial instrument, which is used for 

 railway purposes. On the rest of the Continent 

 the Morse is almost exclusively used, except on 

 some German lines, where they employ dial 

 instruments. 



The great distinction between Breguet's in- 

 strument and Wheatstone's is, that Wheatstone 

 uses the electric force as his motive power to 

 rotate the index, while Breguet simply u-es 

 the current as an adjustive power to regulate 

 the escapement, which directs the number of 

 steps taken by the index, according to the 

 number of currents sent. The motive power 

 is a spring. Breguet, again, uses a battery; 

 Wheatetone, magneto-electricity. They botli 

 work well. Wheatstone's costs sixty or seventy 

 guineas the pair. Breguet's can be had for 

 nearly one-tenth of that stfm. 



The Messrs. Siemens make the finest display 

 of telegraphic apparatus in the whole build- 



ing, and were awarded a gold m. !..!. 



' form ol tubular in.: 



dished or buckled foot-plate i,f MTfOOgi ' 

 which is attached by m. aiis of 

 inm tube forming the lower portion of tin- 

 post, and terminating in a socket t 

 conical wrought-iron welded tn' 

 in the socket by means of a liquid sulphur-iron 

 cement. The post stands about 1C IV et above 

 ground, and weighs about 1J cwt. Many of 

 them are now on the way out to Aby>Mnia, 

 to maintain permanent telegraphic communica- 

 tion with the expedition that i.i sent into the 

 interior. 



Among the apparatus exhibited for testing, 

 and more exact purposes Brid;. '<. Wippe"-. 

 and Galvanometers there is one that merits 

 particular attention for its novelty and great 

 utility, viz., the Pesistance-meaturer, which i- 

 based upon a simple differential method, and 

 supersedes the- use of resistance-coils. The 

 one at the Exhibition measures distances be- 

 tween and 15,000 Siemens Brothers' units. 

 Any one of ordinary intelligence can adjust a 

 needle to zero, and read off the graduations of 

 a scale. It can also be adjusted to either ohms 

 or mercury units, so as to avoid the present 

 troublesome calculations. 



Submarine Cables. The first practical cable 

 was that laid between Dover and Calais in 

 1851, and that continued for many years t" 

 be the pattern of all succeeding cables a little 

 heavier or a little lighter, according to the 

 whim of the engineer. But after the i'ailure of 

 several expensive cables, the Atlantic (1858), 

 the Red Sea (1860), and various cables in the 

 Mediterranean, reason began to rule, science 

 and mathematical reasoning stole in, and vast 

 improvements were the result. It is, however, 

 a very interesting fact that the original Dover 

 and Calais cable is still at work, and for that 

 particular locality a more perfect cable could 

 scarcely have been constructed. Indeed, with 

 slight alterations internally and externally, 

 chietly in the use of stranded instead of solid 

 wires for conductors and outside protectors, it 

 will probably remain the type of all future shal- 

 low-water cables. 



Hattier and Co. are the only cable-makers of 

 any reputation in France. Their first cables 

 made in 1859, and laid along the coast of 

 Brittany, connecting together the semaphore 

 stations still maintained on the French coast, 

 and have continued in good working order from 

 that period. They exhibit a case containing a 

 large variety of cables, most of them of Dover- 

 Calais type, and none exhibiting novelty in de- 

 sign, though great excellence in workmanship. 



Henley exhibits a very tine ea>e containing 

 specimens of every cable ho has ever made, 

 from that laid in 1857, between (Yylon nud 

 India, to the shore end of the Atlantic cable, 

 and that recently laid to Norderney, on the 

 Hanoverian coast. The latter cable is 

 i.ias-ive and strong, and a fine specimen of a 

 heavy shallow-water cable. It weighs 10 tons 



