Recent improvements have done much to render the Davy lamp a more perfect instrument of safety. These more or less insure increased illumination, prevention of bad usage by locking, and more perfect combustion. By an ingenious contrivance, one of these improved lamps cannot be opened without previous extinguishment. Unfortunately, the fatal effects of this rashness are not confined to the foolhardy miner who thus casts away the shield that preserves him from danger, but generally extend to many of his innocent comrades. In the year 1856 an explosion which took place in the Cymmer coal-pit killed 110 persons, and in the year 1857 170 workmen in the Lundshill colliery were swept from life to death with the rapidity of lightning. In the year 1858 the fire-damp levied a contribution of 215 victims in the coal-pits of England, while in 1859 it was satisfied with 95. But in 1860, as if to make up for this deficiency, it raged with double violence; for, after having already claimed a tribute of 80 lives, the dreadful explosion which took place in the Risca Colliery on December 1 destroyed no less than 142 men and boys. The fire-damp explosion which occurred at the Oaks Colliery in 1866 swept away the unprecedented number of 361 victims, and in the same year 91 workmen perished from the same cause at Talk-o’-th’-Hill Colliery. In these dreadful catastrophes the most terrible agent of destruction is not always the burning and concussion of the actual blast of fire-damp, but the choke-damp which succeeds the explosion. For the carbon of the inflammable gas, uniting with the oxygen of the air, produces that deadly poison, carbonic acid gas, which, from the disturbed ventilation of the pit, soon spreads far and wide through the galleries; so that the poor colliers who are caught in an exploded pit have two chances of death against them—one from burning, and the other from suffocation. The effect of death by the one gas or the other is very distinctly seen in the countenances of the dead. The men killed by the fire-damp are marked with burns and scorching, and their features are more or less distorted or disfigured. On the other hand, where men have been suffocated by choke-damp, their features are placid and simply inanimate. The fragile and faulty separations (whether doors or stoppings of any kind) having been broken down, there is an end to a hope of safe retreat even for men totally unharmed by the flames, for at once the air takes the shortest course between the entrance and exit, and leaves the shattered parts unventilated. Whatever after-damp is then and there generated exerts its effects in full, and those who cannot rush to the shaft are suffocated. In the explosion at Risca it was declared by the surgeon to the pit that of those who were killed no less than seventy persons died from the effects of after-damp who had not been near the fire. In the great Haswell explosion, several years since, seventy-one deaths out of