UTAH ACADEMY OF SCIENCES WE 
fragile which rendered the renewal cost rather high. This 
defect, however, was remedied by a discovery made in 1912 
by the General Electric Company in which tungsten, one of 
the most brittle metals, was rendered so ductile that it was 
possible to draw it out into very fine wire, down even to 
.001 of an inch in diameter. Thus, the second period in 
the development of the tungsten lamp began under the new 
name of the Drawn Wire Tungsten lamp. 
The tantalum lamp ceased to exist almost immediately 
after the appearance of the tungsten lamp in 1908, and the 
drawn wire tungsten of 1912 practically eliminated the car- 
bon lamp. The arc lamp was driven from the field of in- 
door service by the Gem lamp so that since 1912 the tungsten 
lamp has continued to enjoy a complete monopoly of indoor 
electric lighting. The arc lamp held its place in outdoor 
service until 1914, when the incandescent lamp engineer, 
not content to rest from his labors until his lamp was made 
serviceable for outdoor as well as indoor lighting, dis- 
covered that a light bulb filled with an inert gas gave as 
brilliant a light as the arc, and that without materially 
affecting the efficiency or the life of the lamp. This is 
known as the Mazda C or gas filled tungsten lamp, and 
owing to the presence of the gas can be raised to a very 
much higher temperature with scarcely an appreciable dis- 
integration of the filament, thus giving a high degree of 
illumination throughout as long or even longer life. This 
fact enables the manufacturer to put out lamps up to any 
desired candle power. The highest power lamp on the 
market at the present time is the 1000 watt lamp, but 
there is no reason why an even higher power lamp could not 
be made if such were desired. Within the last year efforts 
were made to produce this same type with a wattage suffi- 
ciently low to be made practicable for ordinary service with 
the result that a 75 and 100 watt lamp were placed on the 
market and are beginning to attract attention already. The 
arc lamp therefore having apparently reached the limit 
of its possibilities is fast disappearing; and the time is un- 
doubtedly near at hand when it will have become an his- 
toric relic to be studied merely for the purpose of compari- 
