ropuldr rx'icnci' JMonllihi 



703 



This remarkable picture, which looks so much like a glorious sunset or cloud effect, is in reality 

 a great pile of coal in flames at Superior, Wis. It was finally put out with bicarbonate of soda 



Extinguishing Fires in Coal Piles 

 with Bicarbonate of Soda 



IT has long been known that as the re- 

 sult of spontaneous combustion fires 

 often originate in the interior of large 

 coal piles, especially when the coal is 

 fine and contains a large percentage of 

 sulphur. Some of the recent coal-pile 

 fires have demonstrated, however, that 

 under favorable conditions spontaneous 

 combustion is liable to take place even 

 in piles composed of coal in large lumps. 

 It depends principally upon the nature 

 of the coal and upon the amount of rain 

 to which the pile is exposed. 



John A. Thomas, of Columbus, 0., 

 who made a special study of spontaneous 

 combustion, is the originator of a simple 

 and effective method of extinguishing 

 such coal fires. The application of his 

 method has prevented enormous damage 

 in several instances, where fire had 

 originated in large accumulations of coal. 



Mr. Thomas uses a strong solution of 

 bicarbonate of soda, which he tnrows upon 

 the burning coal-pile by means of a force 

 pump. The carbon dioxide, released from 

 the soda puts out the fire. The gas is assist- 

 ed by the water which, by the heat of the 

 burning coal, is transformed into steam. 



The illustration shows the burning coal- 

 pile at Superior, Wis. A considerable 



part of the 100,000 tons comprising this 

 pile was saved by Mr. Thomas, after the 

 fire had been raging more than three 

 weeks in the interior of the pile. 



Why It Is That Bricks Are Made 

 with Straw 



EVERYONE is familiar with the story 

 of how Pharoah commanded his 

 taskmakers to increase the burdens laid 

 on the Israelites by withholding from 

 them the straw wherewith to make 

 bricks; and doubtless many have won- 

 dered wherein the hardship lay. By most 

 people, probably, the view has been held 

 that the straw was added as a binding 

 material, much as hair is used in mortar; 

 but such an explanation is scarcely satis- 

 fying when it is remembered that the 

 straw fiber is a very weak one. Alexander 

 Findlay says in his "Chemistry in the Ser- 

 vice of Man" (Longmans, Green and Co.): 



"About fourteen years ago it was found by Dr. 

 E. G. Acheson, to whom we owe the discovery of 

 carborundum and the process of making artificial 

 i^iphite, that when clay is mixed with a cHhite 

 solution of tannin, it becomes much more plastic, 

 and the strength of the dried brick is, moreover, 

 greatly increased. Although straw does not con- 

 tiiin tannin, it was found that when straw is treated 

 with water, the extract obtained has the same 

 action on clay as tannin has, the plasticity of the 

 clay and the hardness of the brick being greatly 

 i!i creased." 



