EVENING DISCOURSES. 
FRIDAY, SEPTEMBER 12. 
Explosions in Coal Mines and the Means of Preventing them. By 
Sir Henry Cunyneuame, K.C.B., Chairman of the late Royal Com- 
mission on Mining Accidents and of the Eskmeals Dust Explosions 
Committee. 
The object of the lecture was briefly to outline the nature of the experiments 
carried on at the Government testing station at Eskmeals, in Cumberland. 
It has been proved that coal-mine explosions were generally due, not to gas, 
but to clouds of the fine coal-dust which, when raised into the air, made it 
explosive. 
Methane, or fire-damp, the gas usually found in mines, when exploded with 
air gives rise chiefly to carbonic acid and steam. 
But coal-dust, when exploded with air, produces in addition a large quantity 
of carbon-monoxide. 
This gas is very poisonous. Hence coal-dust explosions are usually followed 
by the spread of a poisonous gas throughout the galleries of the mine. As a 
result, when a large explosion occurs, it is found that almost all the men have 
been killed, not by explosive violence but by the painless poison of carbon- 
monoxide. 
It has been observed that coal-dust explosions usually stop short at 
places where, in addition to the coal-dust present, there was also a considerable 
quantity of rock-dust. 
What appeared to be the case was, that when the explosion stirred up the 
coal-dust, it raised into the air the stone-dust also. 
This, however, had a marked effect in preventing the coal-dust from 
exploding. 
Works on a large scale exist at Eskmeals in which experiments were made to 
test how the stone-dust was necessary to make any given quantity of coal- 
dust inexplosive. 
It has been found that this quantity is about 50 per cent. of the total dust 
present, whence it may be concluded that if that quantity is present in the 
dust of any mine, that is to say, if the roadways contain as much powdered 
inert dust as they do fine coal, it is almost impossible, or at least very unlikely, 
that an explosion can occur. 
Experiments were shown illustrating the explosive character of coal-dust, 
and the effect of stone-dust mixed with it in reducing the inflammability of 
coal-dust. 
TUESDAY, SEPTEMBER 16. 
Missing Links among Extinct Animals. 
By Dr. A. SurrH Woopwarp, F.R.S. 
Although the world of life, as it exists to-day, bears many marks of the 
~ changes it has undergone during its past history, most of these are so difficult 
of exact interpretation that it is still necessary to depend upon fossils for a 
real knowledge of the facts. Most of the links in the chain or network 
of life died out long ages ago, and the few of importance which survive are so 
