fRATT.J BRIQUETTING TESTS. 155 
of the briquettes was 6.8 pounds each. The eggettes of this mixture, 
made on the American machine, were better and stronger than the 
briquettes. 
I ml'm mi No. 2. — One ton of this coal was briquetted with 7 per cent 
of pitch H, and the resultant briquettes were satisfactory in every 
way. They were brown in color and resembled those made of Indiana 
No. 1 coal, but were much stronger, due to the better quality of pitch. 
They weighed on the average 6.42 pounds each. 
INDIAN TERRITORY. 
Indian Territory No. 2. — This coal was tested with the hard pitch 
X, using first 8.5 per cent of pitch; but the briquette was not strong 
and crumbled very readily. With 12 per cent of pitch the briquettes 
were not much better, and with 13.1 the briquettes looked well as 
they came from the press, but were not strong and began to lose their 
3orners soon after being exposed to the weather. Judging from the 
runs made, this coal will require more than the usual pressure. The 
briquettes containing 8^ per cent of pitch weighed only 5.08 pounds 
^ach. Those with 13.4 per cent of pitch weighed 6.15 pounds each. 
Indian Territory No. 3. — This coal, which is hard and glossy, was 
ested on the English machine with 8 per cent of pitch A. This made 
'airly good briquettes, which were clean and hard, although some- 
what porous, but they were not so strong as was desired. This 
lefect was due in part to lack of sufficient heat in the pug mill to 
;horoughly soften the pitch. The briquettes as received from the 
nachine weighed 6.56 pounds each. With 7.2 per cent of pitch A, 
;his coal made smooth and fairly hard briquettes, which weighed 6.71 
rounds each. With 6 per cent of pitch A, briquettes were made of 
;his coal that were smooth and well pressed, but soft. These averaged 
n weight 6.8 pounds each. If this pitch could have been heated in 
;he English machine to a sufficiently high temperature to cause it to 
joften and mix with the coal, it would undoubtedly have made a very 
rood briquette; this is indicated by the fact that with a soft pitch, as 
)itch D or pitch H, this coal could be briquetted with 6 per cent of 
)inder. 
Indian Territory No. 6. — This sample consisted of a carload of very 
lirty slack, which contained considerable fire clay and some shale. 
laboratory experiments had shown that 7 per cent of a binder of the 
mality of pitch D was the minimum that could be expected to give 
satisfactory results. Accordingly, one ton of this coal was mixed by 
land with 7 per cent of pitch D, but the resultant briquettes were very 
l|rumbly and not at all satisfactory, although dense and well pressed. 
tjrhey weighed 7.35 pounds each. They were full of gray streaks on 
\ he surface, due to the fire clay, and on standing became coated with a 
leavy gray efflorescence., which was tested and proved to be calcium 
