6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



coal but forced under the stress of shortage to burn egg. His coal 

 requirement became so excessive as to prompt investigation. This 

 revealed that to start with, he used the same draft in the case of egg 

 as with nut, but, failing to obtain the requisite heat, he opened the 

 draft still further. This failed to help matters so he ended by keep- 

 ing all drafts wide open and reconciled himself to the thought that 

 the coal was deficient in heating value. It need scarcely be pointed 

 out that the trouble lay in the fact that the larger size of coal gave 

 free passage to the cold air which kept down the temperature in the 

 combustion chamber and caused the hot gaseous products of combus- 

 tion to pass directly into the chimney. 



What has been said in the foregoing paragraphs relative to the 

 domestic furnace operation applies directly to the use of anthracite 

 coal and along with it the use of coke, its artificial equivalent, which 

 has already made a considerable place for itself and is due for further 

 extension. In using bituminous coal the slide in the coaling door 

 should be left open to provide air for burning the volatile matter and 

 closed immediately thereafter. A further difi'erence of treatment 

 desirable in the case of bituminous is that of firing on one-half of 

 the fuel bed at a time, so as to always maintain a live combustion sur- 

 face necessary to ignite the volatile matter.- Adherence to this 

 special procedure may be made to yield results for low volatile 

 bituminous coals comparable to the use of anthracite, in the matter 

 of smoke. 



Industrial Application 



As coal consumption reaches the stage of tons per day, the attention 

 paid to the furnace becomes practically continuous so that any 

 apparatus which can indicate or guide the operator in the control of 

 the process of combustion can be effectively utilized. In this connec- 

 tion, a report of the United States Fuel Administration, covering the 

 period from September i, 191 7, to March i, 191 9, contains the follow- 

 ing passage : 



The average steam user in the whole United States knows but very little in 

 detail about the operations of his steam plant or its economic possibilities. This 

 has been largely due to the fact that coal has been cheap and in great quantity, 

 and usuall}^ this department has been a small one compared to others. They 

 are beginning to see, however, that a dollar saved in this department is Worth 

 as much as a dollar saved in any other, and we believe that in the near future 

 the power department of the average manufacturing establishment will be 

 given the same attention as any other department. The questionnaires returned 

 to this office show that ninety-Htie per cent of the steam users have but the 

 faintest idea of their actual steam costs, and these plants, as a general thing, 



