330 



THE WORLD'S ADVANCE 



Supplies and Building Materials Were Shipped 

 Bottomed Boats While Building the Road on the 

 the Fraser River. 



altitude of 3,712 feet. These conditions, 

 remarkable from an engineering stand- 

 point, exist in this northern locality be- 

 cause the ranges of mountains along the 

 western portion of the American conti- 

 nent reach their maximum altitude in 

 the region of the 4Oth parallel of latitude, 

 from which they gradually recede to 

 the north, where the Yellowhead Pass 

 runs through them in the region of the 

 54th parallel. Probably the best illus- 

 tration of the varying physical condi- 

 tions as met by various railroads can be 

 shown by the following table: 



or hydrogenation of liquid fats 

 provides a limited market for 

 this hydrogen. 



The great demand for oxygen 

 is for the oxy-acetylene blow- 

 pipe for welding and cutting- 

 metals, Germany, France and 

 Great Britain using 300,000,000 

 cubic feet yearly. The possibili- 

 ty of another great use for oxy- 

 gen was demonstrated in a Bel- 

 gian steel plant just before the 

 war. Enriching the air blast in 

 a pig iron furnace with 21 per 

 cent, oxygen saved 100 pounds 

 of coke to every ton of iron and 

 increased the output of the fur- 

 nace 10 or 15 per cent. Liquid 

 oxygen has also been used suc- 

 cessfully in explosives. 



The evaporization of liquid air sepa- 

 rates the nitrogen and oxygen because of 

 their different boiling points. The prob- 

 lem of a sale for the nitrogen has been 

 solved. When almost pure nitrogen is 

 passed over calcium carbide heated to 

 800 C, the nitrogenous fertilizer, cal- 

 cium cyanamide, is formed. This is al- 

 ready a large industry. Nitrogen can be 

 produced at ten or twelve cents per 

 kilogram. 



A by-product of the liquid air industry 

 is the rare gas, neon. 



in Flat- 

 Banks of 



GROWTH OF THE LIQUID AIR 

 INDUSTRY 



Liquid air is no longer a mere curiosity 

 but a commercial product of great value. 

 Most of it is used in making pure oxygen 

 and in this fluid it has practically driven 

 the older Brim's barium peroxide process 

 to the wall. In fact, the sole competitor 

 is the electrolysis of water, which is a 

 rival only when the other product, hydro- 

 gen, has a ready market. The hardening 



ICELAND SPAR AND LIGHT 



With reference to the general subject 

 of light transmission and pressure, the 

 Museum of Natural History in New 

 York maintains a room devoted to the 

 exhibition of gems and precious stones, 

 which room contains a plate of Iceland 

 spar crystallized carbonate of lime 

 placed just over an incandescent electric 

 lamp. Looking down at the lamp through 

 the spar plate, two lamps are seen burn- 



