CHAPTER XXX. 



FUEL — COAL, WOOD AND CRUDE OIL. 



The location and extent of the establishment wilJ 

 have much to do in determining what kind of fuel will 

 be most satisfactory and economical. 



The use of hard wood, in localities where it is plen- 

 tiful and where coal is dear, may be advisable, especially 

 when flues are used, or in large establishments where a 

 night fireman is employed. For small heabers in which 

 coal is used, the nut anthracite will be preferable, and 

 as the size of the heater increases, a choice must be made 

 between the egg or pea sizes, and bituminous coal. 

 Most of our modern heaters are made for either hard or 

 soft coal, and the choice that is made will depend largely 

 upon the cost of each. In large establishments some 

 form of bituminous coal would probably be used. 



When situated near the mines, some of the low- 

 priced grades of pea or slack coal will make cheap fuel, 

 but they are not worth more than two-thirds as much as 

 good lump coal, and as the freight and handling make 

 up the principal cost of the former, when they have to 

 be transported any great distance, the latter will be the 

 cheapest fuel. 



CRUDE OIL AS FUEL. 



Various devices have been invented for the burning 

 of crude oil in greenhouse heaters. This material can 

 only be used when steam under a moderately high pres- 

 sure can be used to vaporize the oil. In order to use it 

 in a hot water heater, a small steam boiler will also be 

 needed as an auxiliary. One of the best of these burners 



376 



