101 



Table 62 Concluded. 



TANKS, VATS, AND SILOS. 



The market for wooden tanks is broadening in spite of the fact that metal 

 tanks are used to a considerable extent. In no other line is there a greater 

 increase in demand for this commodity than by factories where tanks are 

 needed to furnish water for manufacturing and engineering purposes. They 

 are usually elevated to the top of the factory buildings, but most frequently 

 on towers varying in height according to the pressure desired. Water tanks 

 along railroads are in this class and southern white cedar, cypress, white 

 pine, and longleaf pine, in the order of quantity, are the woods used for 

 the staves. Shortleaf pine and hemlock went for tank covers. Tank staves 

 are made of heavy material, the thickness varying according to the size and 

 use of the tanks. Often the staves are as much as three inches thick and 

 they must of necessity be made of the best grade of lumber since tanks are 

 subject to strong pressure besides continued atmospheric changes, and the 

 influence of water and other liquids has a deteriorating effect. 



In selecting material for tank and vat staves the manufacturer is guided 

 mainly by the use to which the finished commodity is to be put, as there 

 are qualities in the several woods which commend them for certain kinds. 

 The distillers and vinegar makers prefer yellow poplar for keeping-vats, 

 but yellow poplar in some localities is too costly and its place has been taken 

 by cypress and white pine. Brewery vats are usually of cypress and white 

 oak. These woods are durable and strong and have no effects upon the 

 taste and odor of the contents. Where a tank is closed and fermentation 

 active or where one of extra resisting power is needed, white oak is preferred 

 because close grained, heavy, and strong. Southern white cedar is also 

 a favorite and though not so strong as white oak, when used it is strongly 

 reinforced. 



Vats for the manufacture of oleomargarine are of white pine, cypress, and 

 Douglas fir, while those in pickle factories are generally cypress, Douglas 

 fir, and longleaf pine. Individual oil tanks call for white pine, white oak, 



