S(ill/e ve.rv remarkabh, statenlents were, made berlin, the Committee .i' Parliament on l,i~hIinff by l~le(.tmelty. These statements arc. emh,,died ill the report, am{ having gone the rounds of tile pres~ witholtt examination or eoltlment, th( D-will, no doubt, be adopted as settled thet,*. [t is, therefore, v(nw desirable that they should be examined, and that an understanding sh(,dd be arrived at as to how tilr they are reliable, and ill what sen.~e they are true. We will, theretbre, eomlnenee with the renmrks of Sir William Thomson.
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We are anxious t() obtain your opinion Ul)On vt/riolls points (,,)nueete(1 with eleetri(" lightinz; perhaps you will let me go to the ro(,t ()f the matter, and ask you to tell us the energy which is used and ~,xhil)ited as light in the pr.duetion of' the electric are?--The energy which is ae, tuallv used in the ele,(.trie arc is about 1 horse-power per 2t(10 eandle-1)ower , or even more than 2400 eandle-power, aceording to the (tiiuensions :rod other eiremnstanees ()f the eleetrie are.
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That is to say, I horse-power, if' Nllv employed, produces 2-t00 candles or more '.)--Yes, 1 horse-power actually in the electric art ; 1 horse-power spent ill stirring the luminife, rous ether between the ear-I~m point,s and on the surfaces of tile carbon.
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Have v()u at all calculated the energy appearing as light in the ease of the eoml)nstion of gas ?--1 horse-power of enelNy in the ~ombustion of gas produces about 12 eaaldle-power.
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And one horse-power converted into electric light produces 2400 candles ?--Yes.
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As these are rather startling figures, perhaps you will exl)lai~ t. the committee how you arrive at such results ?--Sir William's reply, is too lengthy fi)r full quotation, as the greater part of it is unimportant ; he eoneludes by saying : "The upshot of all is that, allowing the practical estimate of I horse-power actually spent in driving the engine to prodaee 12(10 eandles, whleh has been realized, I estimate that one-Mlf of that power goes to the electric are, and one-half is lost in heatin K different i)art~s of the maehine. This the~ ylve,~ 2400 eandlesfo~' 1 hor.~e-powe~, which is the figure of my 'mswer. In respete to gas I