402 Progress in Science. [July, 
described enabled a determination of the quantity of heat transferred to the 
condenser from each boiler, during its twelve hour’s trial, to be readily made. 
The weights of coal and wood were also recorded as is usual. To ascertain 
the weight of water actually evaporated and that carried over unevaporated, 
the committee use the formula, Hx+h(W-—«)=U, where H is the number of 
thermal units transferred by each pound of steam, / the thermal units carried 
over to the water of condensation by a pound of water, « the weight of steam, 
and W — x the weight of water, by which the total quantity of heat U is trans- 
ferred from boiler to condenser. Introducing other values from the log, and 
solving for x, the results exhibited in the fifth column of our table are easily 
deduced. At the end of the elaborate report of the committee is a very com- 
plete table of results, from which we extrac the following :— 
Bae vay Se 
3 5 3) Die ° oe 5 a. 5 by 
ia) Nas Bald mn eg <8 Bae) wee 
Name. Style. SU tearm unger S32 Sgu 23 
gn ofa) 26 e Baa of 
Set vce aansely ure 5 Pain 
Root .. ‘Sedtional*” 876} 23°59 32°5 o'00 416°6° F. 10°64 0709 
Allen .. “Sectional*” 920 17:41 28:5 o'00 345°8°.F. Fo:60) e707 
Phleger.. ‘‘Sectional*” 600 22°74 26:1 3°26 503°7°F. 10°49 0'699 
Lowe .. ‘Tubulart” 913 21°63 24:2 6:90 389°6° F. 10°40 0°693 
Blanchard ‘“Tubulart” 440 33°48 51°38 3:00 221°6° F. 11°34 0°756 
ELECTRICITY. 
M. Bouman, of Holland, has effeted a considerable improvement in the 
arrangement of the Léclanché cell, rendering the pile still more constant. In 
the flat-bottomed glass jar a plate of gas carbon and a rod of amalgamated zinc 
are placed vertically, a short distance apart. The intervening space and the 
surrounding parts of the vessel are then two-thirds filled with the usual 
mixture of coarsely-pulverised coke and black oxide of manganese. In order 
to prevent the zinc poles from coming into contaé with the black mass, it is 
protected by a cover of woollen cloth. The porous cup is thus dispensed 
with. Léclanché made the connection with the carbon plate by means of a 
covering of sheet lead; but as this was liable to oxidation, complete contac 
was often destroyed. Bouman remedies this evil by cutting a slit in the gas 
carbon pole, and inserting a platinum wire, on the ends of which are clamps 
in connection with the outer circuit. Thus modified, the elements were found 
to run without interruption for a year sufficiently strong to drive an electric 
clock, and to sustain an alarm clock for two years. Mr. Higgs, by arranging 
a series of small-sized carbons and cylinders of zinc in alternate series in a 
similar manner to the series of the old iron-zinc deflagrator, has been enabled 
to dispense with additional celis, at the same time evolving the full ele¢tro- 
motive force. He has succeeded in introducing into one small vessel twelve 
couples of zinc and carbon (adopting M. Bouman’s method of surrounding the 
zinc with felt), thus deriving the eleétro-motive force of about ten Daniell’s 
cells from a very diminutive battery. Batteries exposing a larger surface are 
being made on the same principle. 
An improved method of nickel plating has been devised by Mr. Keith, by 
which he obtains a flexible and tenacious deposit. The deposits at present 
obtained are so brittle that the articles will not suffer the least bending. The 
invention consists in adding to the various solutions of nickel, whether formed 
of single or double salts, materials which by their presence prevent the decom- 
position of the solution of the plating bath, and the deposition of oxide of nickel and 
* Wrought-iron tubes. t With special provision for perfect combustion. 
+Feed-water heater and mechanical draught. 
