68 BULLETIN 102, UNITED STATES NATIONAL MUSEUM. 
disturbing external factors. The production of incidental products 
(waste products and by-products), however, is under no such con- 
trol, but is determined by the output of main products. Hence the 
supply of incidental products exceeds the demand. Industry itself 
tends to bring these incidental products into use, but is limited by 
certain restrictive circumstances. 
The individual industrial activity is often too small or poorly 
organized to make by-product recoveries, which usually gain their 
value from a cumulative effect only possible under large-scale opera- 
tions. If the activity is strong and highly organized it tends to 
build up by-products, in so far as the by-products are end-products 
or near end-products; that is, materials that may be adapted by 
slight treatment to an immediate consumptive demand. Such activi- 
ties may even add small pendant industries in order to make the 
adaptation. Such pendant industries, however, are usually confined 
to operations that may be largely fed by the output of the parent 
industry. 
If, however, the potential by-products are of the intermediate 
order, requiring outside industries to carry them forward into use, 
and these outside industries are lacking, inadequate, or too foreign 
in scope to be built up by the parent activity, the matter of by- 
product development gets beyond the reach of industrial stimulus. 
Such is the case with the bulk of by-product possibilities. The 
parent industry can do little or nothing; independent industries to 
handle such materials are slow to develop, hampered by the un- 
certainties of a supply fluctuating independently of the pressure of 
their demand, and hesitating to build activities at the mercy of con- 
ditions beyond their control . 1 
Apart from the virtual inability of an industry to create a favor- 
able outlet for its potential by-products of the intermediate order, 
there is a lack of definite stimulus to do so, growing out of the fact 
that the loss involved in nondevelopment is not felt by the industry. 
Within an industry, it is true, where the lack of by-product recovery 
is due to the inferior practice on the part of an individual enter- 
prise as contrasted with its rivals, the waste involved does mean 
financial loss to the activity engaged in the inferior usage, and is 
slowly remedied by the operation of continued competition. But 
where the lack of by-product recovery is common throughout an 
industry, there is no competitive spur toward improvement: and 
as the waste involved in the lack of full-value recovery is a loss 
not borne by the industry and not perceived by the public, who for 
the main products pay a price untempered by by-product contribu- 
1 There are other factors retarding independent industrial developments utilizing by- 
products, but these involve matters that need not be gone into here. 
