%ALVAN1C APPARATUS. ' g^^ 



preffion, and find it extremely convenient ; and I have no 

 doubt it will be adopted in a great variety of machinery when 

 its valuable properties are generally known. 

 I ain> 



Sir, Yours, &c^ 



J.J.HAWKINS. 

 11, Nat} Lijle Street, 

 March 17, 1804. 



VI. 



Propofal for cdnjiru6iing a Galvanic Apparatus of Great Power, 

 for the Combujition of Metals. By a Corref pendent. I.R.I. 



To Mr. NICHOLSON. 

 SIR, 



A HE following idea of a mode of increafing to an immenfe Increafe of 

 degree the galvanic power of inflaming metals, took its origin ^y^j*"^^ ^^^* 

 from Mr. Wilkinfon's paper on that fubjefl in your laft Journal ; 

 and I beg that if you think this communication can be of the 

 fmallefl ufe to that ingenious gentleman, that you will fend it 

 to him before publication. 



I can hardly think that it could have efcaped his penetra-by one fiagle 

 tion, (though I cannot account for his omitting theobfervation) P**'^^'^ ?*''• 

 that the natural confequence of his difcovery relative to the 

 ratio by which the galvanic trough increafes in its power of 

 inflaming metals, is, that the maximum of effe<5t wjH be pro- 

 . duced (from a given furface,} by one pair only ; fo that the 

 fame furface of metal that in his apparatus at prefent confirudt* 

 ing and diftributed into 50 pairs, will burn 108 feet of fteel wire 

 •5*^ of an inch thick, if concentrated into one, will have the 

 fame eflfeft on 5400 feet of the fame wire ; an enormous in-f 

 creafe of a power that may become as noble a prefent to the 

 •♦rts, from fcience, as the fteam-engine has proved, 



I ha veal fo turned my thoughts towards making a new form Defcrlptlon of 

 of apparatus, on the above principle, fo as to condenfe it into ^^ propofed ap- 

 as little bulk as poflible.' Thefimple inrpe6lion of the drawing P*^*^"'* 

 accompanying this will fufficiently illuftrate it j the fcale is of 

 three inches to a foot, [PL XV.) it reprefents part of the ground 

 plan of a trough, of about ten feetlong, two feet broad^ and t wo and 

 half feet deep : the black line reprefents the copper, the dotted 



the 



