244 
MAGAZINE OK SCIENCE AND ART. 
of the dynamic force is applied, and by the mechanical 
arrangement of parte successively and continuously 
brought into action in a direct form, in accordance with 
the laws of electro-dynamics. Thus applied, there is 
no loss of primary force, and any amount of power and 
any length of stroke can be obtained. In fact, both 
mechanical and electrical conditions are very simply 
and beautifully complied with, and to this alone is the 
success of the invention due. The machine may be 
simply described as consisting of four galleries, each of 
which contains four groups of four electro-magnets 
which are alternately opposite in their polarities, ami 
which, therefore, by induction naturally react upon and 
augment their collective power. Through these magnets, 
pass rods, connected by connecting rods and cranks to 
the shaft of the engine. Each of these rods has a disc 
or keeper suspended on shoulders above each group of 
magnets. The keepers are made with a hole in the 
centre, so as to slide easily upon the rod, and not im¬ 
pede the motion of the latter when it is receiving an 
impulse from a magnet applied to any of the other 
keepeis or discs. The same kind of action is produced 
on each rod, so that as one completes its portion of the 
stroke the next one is commencing in the following 
manner:—At the commencement of the motion the 
upper keeper is placed so near the first set of 
magnets that when a current of electricity is applied 
to them they draw violently the keeper to them, and 
thus move the rod longitudinally through the space 
which separated them. The next keeper is by this means 
brought within the same distance from its magnet, and 
the current of electricity is at the same instant cut off from 
the former and applied to these, which thereupon draw 
their Keeper to them, and so drag the rod through an 
additional space or distance equal to the first. The other 
magnets and their keepers beneath respectively act in a 
similar mauncr in regular succession, and thus tomplete 
the stroke of the rod, when the next row takes it up, and 
so on, until the four rods have worked in the same man¬ 
ner, and given the utmost both of power and length of 
stroke to the machine. Thu ugh the machines have as 
yet only been fixed vertically, yet it can easily be seen 
that the arrangement of the parts allows it to be readily 
adapted to all ordinary purposes, whether vertical or 
horizontal. 
Thus, as far as the first conditions of power and length 
of stroke are concerned, the machine appears to have 
achieved great ends. One has recently been submitted to 
the Emperor Napoleon and the Directors of the Conser¬ 
vatoire as illustrating the first principles of the machine 
which, it is hoped, is to carry off the French national 
prize of JlizOOO. offered to any who can solve the question 
of the practical utility of electricity as a motive power. 
The success of the competitor there is to be attested by' 
the cheapness with which he can produce his power. 
According to the average price of coals in Paris one horse 
steam power per hour can be obtained for eight centimes. 
The average price of zlne is eighty centimes per kilo¬ 
gramme, and the French conditions for gaining the prize 
are the machine shall work one horse power on an expen¬ 
diture of not more than half a kilogramme of zinc, or at 
forty centimes the hour. This would make the cost of 
the electro motive power in Paris five times greater than 
that of steam, but the many advantages which in other 
respects it possesses over the latter power would more 
than counterbalance the disadvantage. According to this 
rate Mr. Allan's machines In England, where coal is 
cheaper, would work at a cost ten times greater than the 
present average price of steam yet many of our first 
machinists and manufacturers say that the invention of 
electro motive engines at as much as eighteen times the 
cost for steam power will pay largely. .Mr. Allan pro¬ 
fesses himself perfectly confident that he can produce a 
machine not only within the working price we have just 
mentioned, but even within the French conditions He 
maintains that It is an error to consider the cost of electro¬ 
motive power as being relatively less * profitable’ than 
steam, and that the error has arisen from the misappli¬ 
cation of the electro magnetic force, not from the neces¬ 
sary consumption of the electric materials, wh ch con¬ 
sumption is inversely as the dynamical ratios of the force, 
lie considers that the materials, on the other hand, from 
their chemical admixture in the battery, although of no 
practical avail for the production of the electric fluid, 
become when produced on a large scale of considerable 
market value, and when sold realise a large per cordage 
of their original cost. But as the cost of the power is 
thus takeu as the standard of success, the expenditure in 
fairness must be regarded from various points of view. 
Thus, then, we must not forget that In Madrid and Lisbon 
the cost of coni for steam power is twico as dear as at 
Paris! that ia most parts of South America, in India, 
aud China, and throughout the East generally, the cost of 
coal is twice as much as that again, so that in those coun¬ 
tries where an easily managed motive power is most 
wanted, electricity may yet compete with steam on an 
equal or even advantageous footing with regard to cost, 
liut a great reduction i the cost of the power may be at 
once effected by not using zinc at all, since iron when 
used on a large scale as an element in batteries may be 
regaided - s almost equally efficacious with zinc, hut the 
cost of the power must be at present a subordinate ques¬ 
tion—at leasr other and more questio is must be decided 
ere the cost can be fairly ascertained. For instance, Mr. 
Allaa fu,Us that there must b ; a certain relation between 
the electric current and the diameter and the length of the 
magnet, though what these conditions are it is difficult to 
say at present. With only a slight modification of the 
relation of the wire to his magnet, he suddenly found that 
he lost four-fifths of his power. Now, here is a problem 
the solution of which must have a vital influence on the 
electro-magnetic power, and, therefore, in its cost of pro* 
duciion. Vet, these disturbing iuflue.ices, whatever they 
are. were not eveu known to exist u jtil now ; and every 
day the general laws which govern the science of electro¬ 
magnetism are becoming more a^d more fully developed.' 1 
So much for English invention, but we 
aie glad to say that the colony is not 
barren of inventive talent. In our pages 
this month will be found a letter from the 
inventor of a machine applicable to agri¬ 
cultural purposes, which we are assured is 
of very high promise. We can only say, 
that at the advice of those competent to 
form an opinion, the inventor has gone by 
the last mail to England, to take out a 
patent, and promises soon to return with 
an agency, by which the tilling of the soil 
may be effected, without incurring the 
primaeval curse inflicted onhuman creatures. 
Another gentleman claims to have a ‘ New 
Propulsive Agent, as substitute for Steam,” 
and invited the press to witness its power, 
within the last few days. The result has 
never been chronicled, but we congratulate 
the colony on this evident disposition in 
some of its population to go-ahead. 
THE HORTICULTURAL SOCIETY’S 
MODEL FARM. 
Tiie Council of the Horticultural Society 
have issued circulars appealing to the 
liberality (or rather, if they understood it 
rightly, to the self interest) of the inhabi¬ 
tants of the colony, to enable them to 
raise the necessary funds for the establish¬ 
ment of an EXPERIMENTAL or MODEL 
farm and garden. The site has been 
