18 
REPORT—1854. 
battery hjwe been found sufficient to work from Manchester to London. He added, 
• ' advantages over the needle systems are,—it requires only one wire, gives t 
p n e record of all communication, requires but one-fourth the power to actuate 
i and is not interrupted by a comparatively defective insulation. It gains these 
vantages ; 1st. By discharging the line-wire between every movt of the by. 
n . Gravity aiding electricity in making the relay contact, thns using the »un 
instead of the diflerencc of the forces. 3rd. The sliding action of the relay fontiri, 
y rubbing oft the thin film of air, gives sure und instant contact with a very mull 
amount of battery power, 4 th. It will work through a very considerable amount "I 
ea age from one wire to the other, because there is a current always flowni 
_ nrougb the wire, rendering this apparatus peculiarly adapted for wires suspend 
in tne air and which leak from one to the other in damp weather, the surfaces" 
tne intended insulators becoming coated with moisture. 1 ' 
Alter dismissing the mechanical difficulties of laving a cable between Knglwd and 
America, he stated, " I have come to the following conclusions1st. Ifawirecw d 
e suspended in an unbounded non-conductor or atmosphere with uo conductmj 
o°dy near it, the transmission of an electric current through it would be insrantA- 
neous no matter what the length of wire. 2nd. The approach of any conducM.f 
body to this wire would (by induction) reduce the speed of the transmission * 
snown m the 1500-mile experiment. 3rd. In the case of a wire coated with a non¬ 
conducting substance (such as gutta pcrcha), the induction decreases in the Mat 
proportion as the thickness of the coating is increased. 4 th. The conducting I»‘ ff 
fare'' lre 1S 1D proportiou to its Bub stiuice, the induction in proportion to it* *«'■ 
calcu,at ed the dimensions of a cable 3000 miles in length, which wo j | 
diameTr l We S'- flV£ : Words P" minute. " A copper wire one-sixth of an ; 
found p ,nnoi°M W '! h 8 utta pereha to the depth of nearly halt an inch, * ■ 
3000 milps-t iy aiC f °[ m y apparatus of transmitting twenty-five words per 
of an inrli in a- WOIt tl0 n, 'dinarv telegraphs the copper wire must, lie thre - 
b ° th by " 
Notice of some Experimental Ecsearches into the Application of 
Mattery to the Ignition of Gunpowder. By Capt. Ward, M.L- 
ForSationI d r haVing bccn re l«Mt«d by Sir John Burgayne, 
batter v for m’ilibin^ ° Ut SonD ,f e *P er itnents for determining the best rn ^ 
Ohm 'WlwS 5 pU , r P° - ea ' h « nia(le himself fully acquainted vvith h a" 
JEtoPSSi 0t , hcrs ' and > verifying many of their 
parison of ^ le bases for his own inquiries. After a m ■ ,, be' 
zinc and platinum batt l eri 1 ® 8 » he adopted a Grove s battery, the so 1 ^ f'Sheffo* 1 
ascertained that .iT 1 the . l,f * u,d n «tric acid and dilute sulphuric and.'j“ 
aa regards work fni®’ ° nlj ' 2 incht ‘» ^uare, were, perhaps, the most » pf , 
pairsf which xviih .' C09t ‘ Thes " Granges in small elementary batten 
wide, and 4 inches d? conta,, "°B box. occupy a space of only 7 , *J^£? tter i5 f »P* b 
of ignitire- tnm * d / l P' s o that eight or nine of these elementary f or md ? * r 
rurpo ' *£SSZ' t" ,h f *'<*** ■“*-■*»«wr?>«* rc ff d bv ” 1 
carrying outld,,l.f ranBed ai * «P«* of V 2" by 1' 4 or 
form Of batten- Und e *P©«ally in determining the rcI ®! w eCO nduf !l f 
wires ia S; ‘ Pf^y modification of the battery or of rf : 
needle of tho ordinary 0 Ca , or,hc vtlcct « Ca pt. Ward found that tb d ^ fot tfr 
estimation of different g ! l|vunora etcre was so great as to render i currcnli; *n 
he therefore constructed* JV** dectrorae,nc force in ?uch , .PJ^e i< en»W |dt0 1 £ 
terposeone, two, or mml °‘ y aitn P ,c instrument, by which & “ aB d. »*• 
this instrument, in ai3!lLP ,ccw . of th,n platinum wire in the ci . V tera une-t 
relative force ofanv hart<!!.» tl0n w,r * 1 * 5rof - Wheatstone’s rheostat, 
the calorific effect Lhibited’rJtf !‘u ell , a V ,ie resistance of the P. ! ‘ lt,nU ^ es e ' 
d on the fusion of the platinum wire. 
