l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



Disregarding this unreasonable multiplicity of qualities, grades and 

 sizes, the average retail yard is, to say the least, poorly equipped to 

 maintain uniformity in the quahty of the coal it distributes. It is 

 hardly more than a railway trestle dump and is commonly located 

 toward the heart of the city where the growth of municipal fixtures 

 has prevented expansion. The general result is a series of trestle 

 dumps, too few to admit of adequate grading of coal and too low 

 to the ground to admit pocket storage and loading, with the net 

 consequence that the coal of a given type, even though coming from 

 various mines, is dumped together on the ground. 



Samples of bituminous coal gathered from the yards in almost any 

 city will show an ash content ranging from 2 to 20 per cent ; sulphur 

 from less than one-half of i per cent to upward of 4 per cent ; from 

 high fusible ash to low fusible ash; from 15 per cent volatile matter 

 to 40 per cent ; and from almost wholly slack to 70 per cent lump. 

 The group characteristics, volatile matter, ash, sulphur, etc., run more 

 or less uniform for a given mine but vary for different mines even 

 in a given district. Accordingly, the yard procedure just outlined 

 results in the inability to maintain anything like uniform standards of 

 quality. Furthermore the average consumer, in not being educated 

 as to fixed standards, quite naturally lacks adequate discriminatory 

 knowledge of the subject, which, however, has an important bearing 

 on fuel economy. 



Thus has come about a vicious circle in which the consuming 

 interests, not having been educated up to require uniform standards, 

 do not demand them, and the marketing interests, having no call for 

 uniform standards, have taken no pains to supply them. This is an 

 unfortunate situation for, as will readily be seen, it stands in the way 

 of subjecting furnace practice to chemical control. One coal requires 

 a thicker fuel bed, another a thinner bed ; one requires a larger, and 

 another a smaller combustion space ; one requires a weaker and another 

 a stronger draft, and so on. Fortunately there are evidences which 

 point to the dawning of a new era in which standards of service will be 

 developed in keeping with recognized standards of requirement. This 

 will be speeded up or retarded just in proportion as the consumer 

 learns the value of uniform standards. 



The principles underlying combustion and the consequent ad- 

 vantages to be gained by chemical control are applicable all the 

 way from the small household furnace to the largest of power instal- 

 lations. There is this general difference, however, that the latter is 

 under continual observation, whereas the former receives but casual 



