pratt.] BR1QUETTING TESTS. 163 
Although the highest pressure possible was used, the resultant bri- 
quettes were very porous and had the appearance of an incoherent 
mass of chips. With 12 per cent of pitch A the briquettes wore still 
porous and noncoherent, and on standing' lor some time exposed to the 
weather the grains and fragments of lignite began to slack off. Between 
the fragments of lignite there was an excess of pitch observed, but it 
did not seem to have any adhesion for the fragments. As the bri- 
quettes were cooling it was noticed that the contained steam acted 
upon the lignites, giving them the appearance of lumps of soft, brown 
loam surrounded by pitch. 
The next test was made with dry material, the lignite having been 
previously ground to about 4-mesh. One ton of this dry, fine material 
was mixed with 12 per cent of pitch A and run through the English 
machine, only one side of the disintegrator being used. There was no 
excess of steam and the full pressure was used, but the resultant 
briquettes were open. With both sides of the disintegrator in use 
there was a slight improvement in the briquettes, but they were all a 
porous, incoherent mass, and on exposure to the weather began to dis- 
integrate. There was apparently an excess of pitch between the flakes, 
similar to that observed in the first ton tested. The same mixtures 
were tested on the American machine, and the egge ttes, w 7 hen first 
received, had a polished, lustrous appearance, but became rough imme- 
diately, and they had almost no coherence". This lignite was tested 
farther by increasing the percentages of pitch, allowing the mixtures 
o remain longer in the pug mill, and increasing the pressure to the 
imit that could be attained on the English machine, but no briquettes 
vere obtained that had any coherence, and all the results were negative. 
PENNSYLVANIA. 
Pennsylvania JVo. 3. — This sample consisted of a car load of anthra- 
ite culm. The first test was with 90 parts of the culm and 10 parts of 
. West Virginia coking coal, and 12i per cent of hard pitch A. The 
aixture was run through the English machine, both sides of the 
isintegrator being used, and the briquettes being pressed to the limit 
f the machine. On account of the hardness of the anthracite coal, 
; did not disintegrate to any great extent and the resultant bri- 
uettes resembled concrete. These briquettes were hard and tough, 
md even with this inferior pitch were of good quality. They weighed 
n an average 7.25 pounds each. During combustion they burned 
ike lumps of anthracite coal, making but little flame. On standing 
xposcd to the weather the briquettes did not sutler to any extent 
xcept during hard tains, when their surfaces became pitted. Appar- 
ntlv this pitting was due to the wearing away of the softer pitch from 
he harder fragments of anthracite. 
