1836] 



FARMERS' REGISTER. 



291 



ties, such as obstructing parts in the way of its 

 passage down the shaft, it is possible that the lig-ht 

 might be placed in some sale jiari of the mine it- 

 seifj where fire-damp is never found, and from 

 thence be reflected and refracted through the va- 

 rious parts of the mine. I have nuideexi)erin:!ents 

 with tills view, and have found liglit capable of 

 being rertccted, in various directions, with simplt- 

 and inexpensive reflectors; the first reflection re- 

 quires a true paraliolic reflector, but afterwards 

 plain and simple surtaces will do. Possibly, the 

 whole mine and galleries may be all lit b}^ a single 

 light, if not very extensive; but if seven lights of 

 the first order be placed in ihe tbcus of seven true 

 1'2 inch parabolas, and arranged \vithin a circle of 

 3 I'eet diameter, which they may be, I firmly be- 

 lieve one of the longest min'^s might i)e most ef- 

 lectually lighted in every gallery. No one can 

 judge of the power and management ot" this light 

 wdio has not seen it, or possibly conceive its prac- 

 ticability to the subject before us. I .need not go 

 into explanation of the manner of doing it. The 

 committee will remember that, as the angle of re- 

 flection is always equal to the angle of incidence, 

 we may throw the light in whatever direction we 

 please; by this means we may turn it round a 

 corner at right angles, or in any angles suited to 

 the drills the mine happens to be cut into. ,The 

 practical dilHcultics connected with this plan chief- 

 ly, I conceive, are those arising from obstructions 

 in the galleries: one, for instance, is the air-doors, 

 which are necessarily used for ventilation; there 

 is no difficulty, however, in such case in placing a 

 piece of plale-glass in some particular part of the 

 door, so as to admit the passage of the light 

 through it, or a second light may be brought in an 

 opposite direction; again, if the galleries are so 

 low tha* there is not room f<jr the light, coal wag- 

 ons or miners, to pass together, it is possible so to < 

 widen them, or enlarge them, that there would be i 

 a sufficient space for a sufficient quantity of light | 

 to pass; it may be passed through very small I 

 openings by strong concentration, and altervvards i 

 diverged as may be necessary, ! 



Would it not be attended with great expense"? — { 

 No. j 



Less than the ordinary model — I am not pre- 

 pared to say exactly, but I think it would not he 

 more expensive than the present mode. In case 

 the light is not required to be very great, 1 think a 

 light of less intensity might be used, with advan- 

 tage, that would be less expensive than the present 

 oil-lamps. A very simjite but powerful light, is 

 about to be adopted by the Trinity Board for light 

 houses, which, by way of distinction, and in re- 

 ihrence to the place where it was discovered, has 

 been called the "Bude Light." This light produ- 

 ces an intensity 140 times that of the present Ar- 

 gand burner; this ligiit, therefore, may be used 

 where the ramifications of the mine, or greater 

 extent, does not require the first order, namely, 

 the lime light. In some cases, the light from the 

 common Argand burner, placed in a parabolic re- 

 flector, may be sufficient, and in that case it cer- 

 tainly would be cheaper. I am ot opinion, from 

 the experiments and investigations made at the 

 Trinity House, that the light from lime, and also 

 the Bude Litjht, is less expensive than that of the 

 ordinary light, taking quantity and intensity into 

 accGuiit, which may be sub-divided to equal inten- 

 sity with the first; the intensity of the one is 230 



times greater than the other, and the intensity of 

 the second 140; thus one is capable of giving tha 

 same quantity as 290 Argand burners, and the 

 other as much as 140. 



The term Bude Light has no application to the 

 pecular manner in which it is produced? — It is a 

 term simply used todistinguish it. 



From what is it derived.^ — It is produced by 

 striking nascent carbon, evolved in the combus- 

 tion of" oil, resin, or -similar bodies, with oxygen 

 gas. 



You have spoken of difficulties in the introduc- 

 tion of this new system of liixhting in the mines 

 of this country; apply your mind lor a moment to 

 the difficulties which might arise in the mines not 

 having above two or three feet depth of seam? — I 

 tlunk such diiRcuIties are to be overcome by in- 

 expensive boringor widening to admit the light to 

 pass; in such a drill; a stream of light, highly con- 

 centrated, of six inches diameter, would be ample, 

 and wdiether it passed by the side or the top of 

 the gallery, it matters not. A large quantity of 

 light, by simple means, might be concentrated in 

 such case, and passed along such an opening, and 

 aflerwards diverged in larger galleres, if such 

 was indispensable. These are points upon which 

 I think the committee willl find other persons 

 more capable of giving information on than my- 

 self. 



Supposing a light is required to be in a straiglit 

 line lor a mile, there would be no difficulty in ob- 

 taining a sufficient light at the terminus? — The 

 light at the distance of a mile would enable 3'ou 

 to read the smallest print. If it is reflected two or 

 three times in that distance throucrh a circuitous 

 passage, you would lose very little, if you use 

 good reflectors made of specuhiin metal. The 

 quantity of light lost by such reflection is very tri- 

 fling. 



The question related to the casting of light 

 upon one object at the distance named? — So I 

 have answered it; it is of little consequence whe- 

 ther it be straight ahead, or at the end of a curved 

 or angular gallery. 



In case that light is then to be divided info fifly 

 difflsreut directiotis, so as to suit different galleries, 

 what would be the consequence as regards the 

 terminus? — The result would be, that the light 

 would simply be reduced fifty times in quantity; 

 it would be "divided into fifty portions; it would 

 then be still stronger than the strongest Argand 

 burners; and I beg to be understood as meaning 

 the Argand burner used on the tables of private 

 families, not the little oil burner of the safety-lamp. 

 I will make an observation here which may lie 

 important, namely, the stream of light may be 

 sent through the various galleries, and when it 

 arrives at the situation v.^here the men are work- 

 ing, every man, with a little reflector or refractor, 

 as'may be determined on, may take that portion 

 of light which may be intended lor liim, and no 

 more, from the great stream, and thus limit liim 

 the quantity of light that he may abstract from 

 the stream; wliich portion he may at pleasure di- 

 rect wherever he pleases on the work before him; 

 so that instead of a lamp, he would work with a 

 little diverging reflector, or refractor, which he 

 would carry in his jjocket, perhaps of the size of 

 ha!f-a-crown. 



Do you not think that the experiments of sci- 

 ontillc men might be belter made in the mines 



