. 
four-horse. Further addition of battery would still augment the 
power, and I see no reason why ten horse power might not be 
obtained from this engine, by the addition of more-battery ; but 
Whether it would be economical to increase. power by this means 
alone, and to ascertain the point, for this and every other engine, 
beyond which economy would cease by increasing the battery, — 
alone, are matters to be determined by experiment. 2 Te 
The next most important point to .be determined was the ex- 
the expense was found to be less than the most expensive s 
engines, although recently, in Europe, it has been decided by ex-_ 
petimenters and men of science, and generally conceded, that it 
was fifty times the cost of the dearest steam*engines; but this is 
no obstacle to its introduction, considering its immense advanta- 
Ses in other respects. Moreover, if thus much has been done in 
le Very inception of this undertaking, what may we reasonably 
__.€Xpect from its further prosecution ?* A eS 
i aged it can be rendered available in practice, much remains 
to be done with the galvanic battery, to render its action regular 
abd durable, and in other ways to establish a certainty of action, 
__ 80 that the engines ‘may be managed by persons not thoroughly 
Skilled in the subjects of electricity and magnetism. 
__ It remains yet also tobe proved whether the power will in- 
Crease in proportion to thé size of the engines. ‘This principle 
Seems tobe strongly indicated by ‘past experiments; but yet it 
cannot be established by caleulation or process of reasoning. Ex- 
periment upon ai extensive scale can alone determine this point. 
A part of the work preparatory to building a locomotive engine 
has none; but it seems necessary to try further experiments 
* Prof. Page, a8 mentioned in our last’ nuniber, statéd in his remarks before the 
American Association, that one horse power for twenty-four hours, would cost about 
f. W. R. Jo that his estimate was based upon too 
2 cost for the zinc, and that 10 cents would be a nearer estimate. In either case, a 
aot advance is made upon’all previous experiments. ' 
f. age also observed, that the cost of electro-magnetic power was not to be 
reckoned in this comparison by the mere cost of zinc, nor the cost of steam by the 
ds of coal consumed. The cost of human life, the sacrifice of millions of m4 
and risk of many millions more, and all the contingent advantages and 
0 account. 
: mode of me 
plained tas follows after drawing a diagra 1 2 
load lbs. The power required to barely keep the engine in motion under this 
min nt 126 Ibs. The full power being on, the engine made eighty revolutions per 
