PROCEEDINGS 1849 — 1858. 
273 
the paper Mr. Carter stated that he quite agreed with the principle 
enunciated by Mr. Brackenridge, and was astonished that their two 
schemes should be almost identical. Mr. Henry Briggs was afraid 
that Mr. Brackenridge had not made any provision for throws or 
fractures of the stratum. He thought the suggestion of carrying off 
the gas to the rise a very excellent one ; still, there were practical 
difficulties regarding its escape. In his (Mr. Briggs') colliery they 
found the straight w^orks a very great expense, but they were neces- 
sary for the safety and comfort of the men, and therefore expense 
was a secondary consideration. Xo doubt the best ventilation was 
that of the cupola fire, but there was the danger attending it that 
the men would allow the fire to go down and thus stop the ventila- 
tion. There was also considerable difficulty in the propping of various 
kinds of roofs. In one, as soon as the props were taken away, the 
roof fell nearest to the working surface ; but in another instance the 
roof was so hard a rock that they could work seventy yards square 
without a prop. The roof was a most dangerous cause ; when it did 
come it brought with it an immense quantity of gas, which was liable 
to rush upon the men. That was the kind of goaf which required 
ventilation ; whereas, w^hen the roof fell close, ventilation was un- 
necessary. There was danger in the continuous working of a mine, 
because when, as at Lund Hill, a mine was w^orked night and day, 
the trap doors were being continually opened, the current of air was 
as constantly baffled, and the air of the mine became in an impure 
state. Let that go on long enough and an explosion was inevitable. 
Beyond doubt the principle of Mr. Brackenridge was the best, of 
commencing at the far end, in the first instance, and working towards 
the drawing shaft, because the men were leaving the old workings 
behind them ; when they were escaping from an explosion there was 
a clean road for them to run, devoid of old workings. By the old 
system of working from the down-cast shaft, where one man was 
burnt by an explosion, twenty to thirty were smothered by the choke 
damp. In his Whitwood mine, worked upon the principle advocated 
by Mr. Brackenridge, they had had no miners smothered, and only 
two or three killed. Mr. Jebson objected to the plan on account of 
the difficulty of applying it to such large estates as were sometimes 
