430 MINERALS YEAEBOO~

coal declined appreciably although not necessarily to the extent indicated
by the figures for the total production in these counties.
Coke-oven byproducts.—This discussion is confined to the products of
coal obtained in the high-temperature byproduct ovens. These products fall
into five general groups, some of which are further subdivided. They are:
(1) TarL (2) ammonium sulphate and ammonia liquor, (3) gas, (4) light oil
and its derivatives, and (5) miscellaneous products. In value these products
represent a total almost equal to that of byproduct coke itself; in 1932
their combined~value per ton of coke produced was $4.13 compared with $4.89
forithe coke. In 1913 the value of byproducts was only 27 peroent of t~he
total gross
~-6as çAmmonia 1tar

1913 [~0.45 ~~o~.'Other
9 14 1  54 ~ .26 ~ ~BenzoIproducts
 l915[ .61   ~ _____
 $916 .57 ~
 $917 5' ~~25 ,
 1918 .53  .
 1919 ( .66
 1920 .05 ~ .43~6~
 192$ [ .3~ .55
 1922 [_~ .35 45
 $9231 .37  .51
 $924 .46  .57
 $925  .54 69~~ .59
 19261 .46  .60
 1927  .60  .66
 1928 —  :58 ~.57~\\~ .69
 1929 j .58  .65
 930   .75  .66
 $931 L 2.08 ~a44~ .64
 19321 2.56 [~.3p~ .57

FIGURE 33.—Gross value of the several byproducts perton of byproduct
coke produced, 1913-32.

value of all products per ton of .coke produced. In 1932 their share had
risen to 45.8 percent. (See fig. 33.)
 The average gross value of the byproducts per ton of coke produced increased
from $3.86 in 1931 to $4.13 in 1932; however, this increase was due to the
increase m the average realization for gas from $2.08 to $2.56 per ton of
coke produced. These averages represent the composite realizations for gas
produced by all byproduct plants. In normal times the average price for gas
is dominated by the large establishments associated with iron furnaces at
which gas is credited at relatively low prices. With the decline in operation
of furnace plants the proportion of the total byproduct gas contributed by
public-utility and city plants has increased. Since the price of such gas
delivered to city gas lines is higher than that used in interplant transfers
at furnace plants the average return for all byproduct gas produced in 1932
shows a substantial increase over that in 1931.