. The quarterly journal of science. sent, may beof incalculable moment. If therefore we can iucrease the power ofour lights so as to make them pierce the gloom but that fraction ofa mile further than they do at present, we are moving in the rightdirection. On that small amount of extra offing, hundreds of hvesmay depend. It would appear as if the electric light was pre-emi-nently adapted to meet a case like tliis; but, recently, doubts have beenthrown on its superiority over oil in penetrating fog. In 1865, , the Secretary to the Trinity House, said, that, for a limitedrange of from
. The quarterly journal of science. sent, may beof incalculable moment. If therefore we can iucrease the power ofour lights so as to make them pierce the gloom but that fraction ofa mile further than they do at present, we are moving in the rightdirection. On that small amount of extra offing, hundreds of hvesmay depend. It would appear as if the electric light was pre-emi-nently adapted to meet a case like tliis; but, recently, doubts have beenthrown on its superiority over oil in penetrating fog. In 1865, , the Secretary to the Trinity House, said, that, for a limitedrange of from nine to ten miles, the electric is immensely superiorto any other light, but beyond that distance it appears to lose in agreat degree its power, until at eighteen or twenty miles it is notvery difierent to any ordinary first-class light; and Mr. Stevensonlikewise states, that at great distances the oil light maintains itspower better than the electric. Such a phenomenon certainly seems OuartBrlv of Science N° TJ^ Fcff. c 4C. MuJiJUU i Ut4i^ _ WILDES MAGNETO-ELECTRIC Jv^HINE 1866,] Wildes Magneto-electric Macliine. 501 to be very improbable, altbough it may be tbe case that the rays pro-ceeding from the electric Hght suffer so much more from absorptionin passing through an obstructive medium than those from a flameproduced by the consumption of oil, as to leave the oil light themore powerful of the two at great distances. If this were reaUy so,it would foUow that the application of the electric spark to light-house illumination is based upon a fallacy. The mere glare orsplendour of effect to a near observer, so far from being an advan-tage to the mariner, is a positive evil, because, by its lustre, it tendsto destroy his powers of perception of objects in the water that arenearer his view, and which therefore, from their proximity, threatenmore immediate danger to the safety of his vessel. All the marinerrequkes is distinct visibiHty. The really useful power is tha
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectscience, bookyear1864
