OCR Text |
Show CURIOUS DEVICES I USED FOR SEEIN AFTER DARKNf It is presumed that man nally toiled or played only di hours of sunlight. That when ness came and the eyes coul( longer see he lay himself i to rest. Yet all the while, Nai through volcanic and me; disturbances, through flash? lightning, was trying to de-strate de-strate to man its power to c-light c-light in the midst of darknes? Fire was discovered, and found he could prolong the with the aid of firebrands, c: fires, torches. The earliest lamps of whid have record were saucer sh; objects with a shallow projec spout which held the wick. A in the center of this disc-like 1; held a small quantity of oil So far as is known, there no radical development tov, better lighting until 1783 A. when Leger of Paris devisei j flat ribbon wick and burner, j long after, Ami Argand of P; ! perfected a glass chimney wl together with his new impn type of circular wick and bur: produced illumination far s. rior to anything ever before s; Then- in 1 880, Auer Welsbach, a German, develop? burner, in which the comfe: of a mixture of air and p; vapor, heated to incandesces mantl3, composed of thoria ceria. Welsbach's mantle was, course, crude and inefficient co pared to present-day mantles. J to Welsbach, should go much the credit for making available us today, the pure white li; which is so easily and ecora cally provided in modem press j mantle lamps using gasoline af kerosene for fuel. j . |