I have at last obtained a complete model of my lamp, after many disappointments from the instrument-maker. I hope in a few days to send you a _Safe lantern_, as portable as a common-made one, and the perfect security of which is demonstrable. I am, my dear Sir, your sincerely obliged, H. DAVY. TO THE SAME. Grosvenor Street, December 15. MY DEAR SIR, I shall inclose the first sheet of my paper, and shall be glad to preface it by some observations when you reprint it. I shall forward my lanterns and lamps to you in a few days. They are _absolutely_ safe; and if the miners have any more explosions from their light, it will be their own fault. You will find, when you see my construction, that the principles as well as the execution are entirely new. You will find in the second sheet of my paper, which I hope to be able to send to-morrow, the _principles_ of _security_, and its limits unfolded. I am, my dear Sir, very sincerely yours, H. DAVY. TO THE SAME. London, January 1, 1816. MY DEAR SIR, I fear you will have accused me of procrastination in delaying to send you my papers and my lamps. The papers read to the Royal Society have been printed; but during the period that has elapsed since I last wrote to you, I have made a discovery much more important than those which I have already had the honour of communicating to you. I have made very simple and economical lanterns, and candle guards, which are not only _absolutely safe_, but which give light by means of the fire-damp, and which, while they disarm this destructive agent, make it useful to the miner. This discovery is a consequence of that which I communicated to you in my last letter on the wire sieves. I hope to be able to send you on Wednesday the printed account of my results, together with models of lamps which will burn and consume all explosive mixtures of the fire-damp. I have at last finished my enquiries with perfect satisfaction to myself, and I feel highly obliged to you for having called my attention to a subject where my labours will, I hope, be of some use. I am, my dear Sir, very sincerely yours, H. DAVY. It is impossible to approach the consideration of this last, the most signal and splendid of his triumphs, without feelings of the highest satisfaction. He had already, as we have seen, disarmed the fire-damp of its terrors, it only remained for him to enlist it into his service. The simple means by which this was effected are as interesting as their results are important.[35] [35] "An Account of an Invention for giving Light in explosive mixtures of Fire-damp in Coal Mines, by consuming the Fire-damp." Read before the Royal Society, Jan. 11, 1816.