M’GAULEY’S OBSERVATIONS REFERRED TO BY O’SHAUGHNESSY. 431) 
KFIK TS 
No. 
VVfijjhi sustariied. 
1 For ivli.ii, lime. 
Attiactiiig distance. 
1. 
9 li.a. 
1.') iiiinuU's. 
Email. 
•2. 
1,> ItiS. 1 
2 or S iiiiniiies. 
smalt . 
S. 
llutK'. 
4. 
none. 
5 . 
none. 
fi. 
3s 
2 lionr.8. 
great. 
7. 
9 
I5 oiiiMite.'’. 
small. 
8. 
‘25 
neailj 3 lii,nis. 
small. 
9. 
Kxpei Inu'iits not vet completed, luit salisl'ac- 
tory. 
10. 
No effect. 
11. 
IS IlH. 
.4^ iK.iira. 
moderate. 
12 . 
10 llKS. 
3| iioni.8. 
loog. 
13. 
9 11)8. 
Until Zinc dissolved. 
long. 
These experiments were repeated with cor- 
responding results on electro-magnets of every 
variety of shape, and weighing from half sn 
ounce to 18 Ihs. 
Combinations of several of the previous 
batteries were also tried. I'lie Cruickshank’s 
troughs and cells, multiplied to any number, 
were invariably useless. But Daniel’s cans 
and Wollaston’s double plates gave very 
different results. Thus, though one Wollas- 
ton plate supports l3 lbs., ten of these plates 
support 38, and twenty plates 47 lbs. There 
are, I may mention, two modes by wliich 
these batteries may be associated, as is well 
known of course to all experimentalists in 
this department of science. One is the che- 
mical, where the batteries are arranged end to 
end, the terminal copperplate of one being 
connected with the zinc of the next. The se- 
cond is the magnetic, in which the troughs are 
placed side by side, and the final co[)per cells 
and zinc cells connected with the cells of the 
same name. 
Numerous experiments were made to ascer- 
tain whether doubling, tripling, or quadru- 
pling the number of troughs in either of 
these ai rangements gave a proportionate in- 
crease to the magnetic force imparted to the 
soft iron. The most conclusive of these trials 
was made with the apparatus previously de- 
scribed, (see fig. 2) VV iiile in the chemical ar- 
rangement the successive addiiions made but 
a trifling increment to the sustaining power, 
the second or magnetic arrangement gave 
very nearly a direct increase for every addi- 
tional battery. 
The copper and lead arrangement No. l2 
was formed for the purpose of regaining from 
the solution the materials employed in the ex- 
citement of the galvanic action. The expe- 
riment answered so well that I mean to have 
a battery constructed on this princpie, by 
which 1 have no doubt 1 can recover a very 
great proportion of the acid and lead used, 
because the nitrate of lead formed, yield.s its 
acid at a red heat, and the rnetal is readily 
recovered by smelting the residue with char- 
coal. 
On the whole, as far as my experiments 
have proceeded, they shew that, contrary to 
what is stated by all authorities on this subject, 
’‘‘quantity''' of electricity (that amount set in 
motion by asingle pair of plates) is not the 
sole influence required for the induction of 
great magnetic power. “ Intensity,” or the 
impetus given to quantity by increasing the 
number of plates, within certain limits 
seems equally, if not more, essential. Inten- 
sity adds to the sustaining power, and, 1 find 
by many experiments, increases the attractive 
distance. Nay more : — in almost direct con- 
tradiction to what has been stated by writers 
on this subject, I have reason to believe we 
may diminish the size of the plates even to 
one square inch of surface, provided we asso- 
ciated a numlier of these plates, as in Wol- 
laston’s arrangement. But the details on 
these curious points 1 must reserve for ano- 
ther paper. 
With respect to the economy of the mate- 
rials used, I may refer to Mr. M'Gauley’s 
interesting observations in the Appendix, 
In corroboration of bis views I may slate, 
that sulphuric acid is now sold in England 
for one penny the pound ; at which rate, and 
at the present cost of zinc, 1 would work my 
model, lifting a pound weight for twelve hours, 
for about, one shilling. Should we succeed 
in con.structing locomotive engines on the 
plan T have attempted to point out, the mate- 
rials will be more economical than the cost of 
steam, in the proportion at least of four to 
one. 
I am happy in being enabled to add, that, 
the subject is now engaging the attention of 
one of our most distinguished engineer offi- 
cers, a gentleman whose genius, acquirements, 
and opportmiitie.s give the amplest promise to 
all his undertakings. I am myself sanguine 
as to the result ; and though 1 feel that full 
success in the attempt is beyond my capacity 
and resources, 1 confidently expect to see, 
ere long, the ponderous, expensive, and dan- 
eerous machinery of steam, rivalled by the 
light, economical, and harmless engines which 
electro-magnetism will plaeeatour command.” 
