THE 
LONDON, EDINBURGH ann DUBLIN 
PHILOSOPHICAL MAGAZINE 
AND 
JOURNAL OF SCIENCE. 
(THIRD SERIES.] 
JANUARY 1843. 
I. On the Efficacy of Steam as a means of producing Electricity, 
and on a curious Action of a Jet of Steam upon a Ball. By 
W. G. Armstrone, Esg.* 
APuE experiments which I have made on the electricity of 
steam, since the date of my last communication to the 
Philosophical Magazine}, have completely confirmed the con- 
clusion which I had then arrived at, that the excitation of elec- 
tricity takes place at the point where the steam is subjected to 
friction; and by the improvements I have effected in the mode 
of discharging the steam, I have so amazingly increased the 
energy of the effects, that I question whether any electrical 
machine has yet been constructed capable of producing as 
much electricity as my electrical boiler. At all events the 
boiler has been proved to possess upwards of seven times the 
efficiency of an excellent machine which has a plate of three 
feet in diameter and which was worked at the rate of seventy 
revolutions in a minute when its power was tried. The com- 
parison was made by means of adischarging electrometer, and 
the following tabular statement will convey some idea of the 
quantity of electricity produced in each case. 
Capacity of the jar of the electrometer} a gallon nearly, 
Extent of coated surface on the two 
sides taken together csscccsescceeseees 
Distance of the balls of the electrome- | , bran weal 
ter from each other ssscccccsessrceeee fo) CMs 
Number of discharges obtained per mi- 
nute when the instrument was con- 
nected with the prime conductor of 
the Machine esscccessreverecceveeceeees 
_ * Communicated by the Author. + Phil. Mag. S. 3, vol. xx. p. 5. 
Phil. Mag. 8.3. Vol. 22. No. 142. Jan. 1843. B 
198 square inches. 
29 
