-RATT.] BBIQUETTING TESTS. 151 
The manufacture of briquettes from Arkansas No. 4 coal and 6 per 
3ent of pitch B as a binder is commercially feasible. Six tons of this 
3oal were briquetted with 6 per cent of pitch H, with which to make a 
boiler test." A portion of these briquettes were made by running but 
me side of the disintegrator of the English machine, and as they were 
received from the machine they were smooth and uniform but very 
soft, and on breaking them open there were spots that contained an 
excess of pitch, indicating that the materials had not been thoroughly 
nixed or that in passing from the pug mill to the press there had been 
m opportunity for the pitch to flow together. On cooling, however, 
:hese briquettes became very hard and tough. Another ton was made, 
running both sides of the disintegrator, which made smooth, uniform 
briquettes, but it was almost impossible to handle them as they came 
Prom the machine. Therefore, only one side of the disintegrator was 
.ised, but the materials were run through the pug mill more rapidly 
md better results were obtained. On becoming thoroughly cold, all 
)f these briquettes were excellent in every respect. When these mix- 
tures were tried on the American machine, the fine mass obtained by 
running both sides of the disintegrator made better eggettes than the 
jorresponding briquettes of the English machine, while the coarser 
Material did not make as good eggettes as briquettes. The weight of 
lie briquettes obtained in running both sides of the disintegrator was 
3.92 pounds each, while the coarser briquettes weighed 0.56 pounds 
?ach. The specific gravity of these briquettes was 1.17 and their 
crushing strength w T as 17,500 pounds per square inch. 
Arkansas No. 5. — On account of the success obtained with these 
Arkansas coals and the softer pitches, it was decided to make a suffi- 
3ient quantity of briquettes for a locomotive test on the Missouri 
Pacific Railroad. For this purpose 17 tons of Arkansas No. 5 coal were 
briquetted with 6 per cent of pitch C, which was a trifle harder than 
pitch B. Excellent briquettes were obtained, which were readily 
bandied while warm, and on cooling stood a good deal of very rough 
bandling. They did not break so readily as the original lumps of coal, 
rhe briquettes were tested on a locomotive of the Missouri Pacific 
Railroad, and for comparison similar runs were made on an Illinois 
pun-of-mine coal such as is commonly used on these locomotives. 
Phree trips were made from St. Louis to Washington, Mo. , and return. 
fnaking a total run of 324 miles for each fuel. The results of these 
hree runs are given in the tables following. 
a For result of test see p. 80. 
