754 EAST LESSONS IN CHEMISTRY. 



or Bunsen's electro-magnetic batteries, of which it would require from 100 

 to 150 couples to get an electric flow of sufficient power and constancy. 

 Having satisfied myself of the feasibility of using this method of illumi- 

 nation, the next point was to adapt it to our mountain village. 



To my surprise I found all the conditions for a successful illumination 

 were easily within reach — half a mile from the centre of the town, and east of 

 it is a high, steep table land, crowned by a castellated crag some 600 feet 

 Immediately above the village. Here 1 propose to place the electrical ma- 

 chine, and the electric light in a glass and iron tower, fifteen feet high, 

 placed on the edge of the crag and immediately overlooking the streets. 

 Placed in a semi-circle before the light will be five Fresnel lenses, each of 

 which will concentrate its rays upon a separate district of the town, or 

 five concave specula; either would answer the desired purpose, and all 

 points in the streets and alleys parallel with the rays from the several lenses 

 or reflectors would be brightly illuminated, while the streets crosswise to 

 the rays would have a shadow side. This shadow side I propose to 

 illuminate by having every 150 feet a lamp-post on the illuminated side 

 provided with a reflector, which would thus throw a bright light across the 

 street and prevent any undue darkening of one side in the shadow of the 

 dwellings. 



Another use is suggested for the electric light. In every house or 

 room which presented its end or side towards the electric light, I propose 

 to insert in a hole in the side or end a large glass prism which would reflect 

 the light inside, and thus illuminate the inside of the room brilliantly and 

 intensely, and without the concomitant of fire, explosive j^etroleum or dirty 

 candles'; requiring nothing to keep it in order but a clean cloth or jjiece of 

 buckskin to wipe it; and which would be readily extinguished by a sliding 

 shutter over the aperture. If preferred, the prism can be placed on the 

 roof, and the rays reflected from above inside, as in a church or large hall; 

 or even in a second story school or lecture room. If to some, the intense 

 brightness of an electric flame is too much for their eyesight, tliiMi variously 

 colored prisms can be used to modify the intense light into pleasing soft- 

 ness. We could fhus use blue, green, yellow, brown or opal colored prims, 

 shaded to the exact requirements of an artisan's workshop, or to the 

 taste and optical weakness of individual eyesight. An electric light equal 

 in intensity to 350 candles, would, in Colorado, cost 30 cents per hour. 



Golden, Col., January 26, 1878. 



Easy Lessons in Chemistry. — The following names from a recent Ger- 

 man journal of chemistry will be good practice in spelling and reading for 

 juvenile students of the science: Methylcarbominthioglycolic acid; dini- 

 tribromdiphenylamin ; oxaldiphenylguanidin ; parabrommetasu]23hophen- 

 ylpropionic acid; parapicrylmetanitralin ; ethoxilphenilpropyformiate of 

 paratoluilendiamio ; methylothylpropylamylamraonium oxide hydrate. 



