katt.j BBlQUETTrNG TESTS. 153 
ILLINOIS. 
Illinois No. 1. — Briquettes from this coal were first made with the 
lard pitch X as a binder. One and a quarter tons of this coal were 
>rique-tted with 16 per cent of pitch X, but on account of the softness 
,nd roughness of the coal the briquettes were brown and very soft, 
esembling pressed damp loam. They were, however, compact and 
veil pressed. 
Illinois No. Jf. — Two tons of this coal were briquetted with 6 per 
;ent of pitch 1). The coal was not ground very tine, there being but 
me side of the disintegrator used. There was a great deal of water 
n the steam, with the result that the briquettes were full of the usual 
)erpendicular cracks. Very great pressure was used, and some of the 
)riquettes were larger than the normal size, which was due to the 
:ompression of the spring of the machine. The average weight of 
hese briquettes was 6.95 pounds. The briquettes varied considerably 
n texture, some being hard and firm while others were crumbly. On 
sooling, the briquettes were hard and firm, but would not stand very 
nuch rough handling. The specific gravity of these briquettes was 
.16, and their crushing strength was only 5,100 pounds to the square 
nch. Some of these mixtures were also tried on the American machine, 
,nd the eggettes were better than the briquettes made on the English 
aachine. They were lustrous and had a deep black color. 
One ton of this coal was briquetted with 8 percent of pitch D, using 
'lit one side of the disintegrator and with the maximum pressure. 
Iplendid briquettes were obtained with this combination, but they 
re re gray in color. They weighed 6.43 pounds each and had a spe- 
ific gravity of 1.11. The specific gravity of the coal is 1.34. The 
rushing strength of these briquettes was 9,327 pounds, as compared 
nth. 5,100 when 6 per cent pitch D was used as a binder. The 
^gettes made of this mixture on the American machine were not so 
Strong as the briquettes. 
The next test made with Illinois No. 4 consisted of 2 tons of the coal 
riquetted with 8 per cent of pitch E. The average weight of the bri- 
uettes was only 6.15 pounds. Only one side of the disintegrator was 
sed, and as the coal was hard the briquettes were coarse and contained 
lany noticeably large pieces of coal. The eggettes made from this 
fixture, on the other hand, were much better in quality and quite lus- 
ous, but of a decidedly brownish color. The specific gravity of these 
riquettes was 1.13 and their crushing strength 7,265 pounds to the 
juare inch. To test the effect of finer grinding, another ton of this coal 
^as briquetted with 8 per cent of pitch E, using both sides of the disin- 
grator. In these briquettes there were a few grains of coal as big as 
kernel of corn; but for the most part the material was too line for 
le percentage of pitch, and the resultant briquettes were crumbly, 
