300 TEE POPULAR SCIENCE MONTHLY 



what over sixty-two and one half million barrels were manufactured at 

 about 80 cents per barrel as compared with 85 cents in 1908. 



We are so accustomed to our wooden houses that we dread to have 

 to give them up even when we know that in many other countries they 

 are almost unknown. We are unmindful of Euskin's dictum, " I would 

 have our ordinary houses built to last," as well as, " built to be lovely, 

 as rich and full of pleasantness as may be within and without." We are 

 regardless of the thought that, instead of erecting a structure which can 

 endure 50 to 100 years, it may be better to build for 500 to 1,000 years 

 or more. 



In other ways the chemist is conserving the forests; by guarding 

 against one of the greatest dangers to our wooden edifices — fire — 

 through fire-proofing processes, and against their bacterial foes, which 

 cause decay, through wood preservatives. As to stopping the journey of 

 our forests to the paper-mill, it appears not to be the time for that yet, 

 but chemists are finding ways of replacing wood fiber in paper by others, 

 notably those of grasses. Even if it should prove beyond the skill of the 

 chemist and engineer to continue our present output of paper from 

 the dwindling wood supply and should most of our Sunday papers be 

 forced to curtail their issues, who will see in that any dire calamity ? 



Cement is frequently used to preserve not only wood, but in many 

 places iron, and so conserves this material. Where more strength is re- 

 quired than concrete possesses, iron surrounded by cement has been 

 found to last indefinitely. The process of reducing the crude iron from 

 the ores has been steadily improved so that now, through such means as 

 using the heat formerly wasted from the blast furnace to heat the air 

 of the blast, to make steam and to dry the air before it is blown into 

 the furnace, but a fraction of the coal is required that was formerly 

 necessary. Similar savings have been made in other parts of the metal- 

 lurgical field ; for instance, in the recovery of gold and silver during the 

 treatment of copper and lead ores, several million dollars worth being 

 thus annually obtained, and this by the old methods would have been 

 for the most part wasted. 



The loss of by-products in the manufacture of coke has been re- 

 ferred to ; but closer chemical supervision is rapidly reducing this. In 

 1905 over thirty-seven million tons of coal were coked in the United 

 States, but less than 9 per cent, in ovens where these by-products were 

 preserved. Two years later the amount coked in by-product ovens had 

 increased about one half. 



Foreign chemical engineers are setting us a praiseworthy example. 

 In Gelsenkirchen, Germany, the coke ovens furnish illuminating gas to 

 surrounding cities and villages at 23 cents per 1,000 cubic feet. Each 

 ton of coal yields three to three and one half gallons of benzene, a valu- 

 able substitute for gasoline as a producer of heat and energy. From the 



