ANOTHER EXPLOSION. - The west mine of the Delaware Coal Company is worked three hundred feet below the water level. For some time past the air in this part of the mine had become vitiated and the miners had declined to work in it. Some of the overseers imprudently went down to examine the pit a few days since, when the inflammable gas, or compound of gases-known as the fire-damp, and which had accumulated, in that part of the pit, being ignited by the flame of the lamp, which they carried, exploded with great violence, seriously injuring several persons, besides doing much damage to the works. We are glad there were no lives lost; but we do think the overseers deserved some little punishment for their gross negligence. When the means of effectual ventilation are so conveniently accessible and easily prepared, it appears no less than reprehensible that the laborers in mines should be deprived of the privilege of breathing pure atmospheric air, to say nothing of the danger of explosions. Both money and applause have been awarded to Sir Humphrey Davy, for his invention of what is called a safety-lamp, to prevent explosion of the fire damp; but it would have appeared much more important in our opinion, if he had proposed a plan for ventilation which should have superseded the necessity of the safety lamp, and furnished a supply of breathing air to the laborers at the same time. Nothing more is wanting for this purpose than a large simple hose made of the cheapest kind of plain cotton cloth, extending from the top to the bottom of the pit, with a bell-muzzle, or tunnel shaped tube at the top to be turned by a vane so as to face the breeze. Or, if there be not a breeze sufficient to force a constant current down to the bottom, a spirit lamp, being placed under the lower extremity of the hose-which should extend to within one or two feet of the bottom,-a current will be readily produced upward, and consequently a corresponding quantity of fresh air must be drawn down through the open avenues. But even admitting that mechanical power was required to maintain a wholesome ventilation, it would be bust light work for a man or boy, by turning a crank connected with a flow-wheel or large bellows when there was not a sufficient current of wind to effect it. We hope those of our readers who have any friends employed in the mining business, will suggest to them the impropriety of exposing their lives by working in damp mines without proper ventilation.