As to the value of the invention of the safety-lamp there could be no doubt, and the colliery owners of Durham and Northumberland, to testify their sense of its importance, determined to present a testimonial to its inventor. The friends of Sir H. Davy met in August, 1816, to take steps to raise a subscription for the purpose. The advertised object of the meeting was to present him with a reward for the invention of _his_ safety-lamp. To this no objection could be taken; for, though the principle on which the safety-lamps of Stephenson and Davy were constructed was the same, and although Stephenson's lamp was unquestionably the first successful lamp that had been constructed on such principle, and proved to be efficient, yet Sir H. Davy did invent a safety-lamp, no doubt quite independently of all that Stephenson had done; and having directed his careful attention to the subject, and elucidated the true theory of explosion of carbureted hydrogen, he was entitled to all praise and reward for his labor. But when the meeting of coal-owners proposed to raise a subscription for the purpose of presenting Sir H. Davy with a reward for "his invention of _the_ safety-lamp," the case was entirely altered, and Stephenson's friends then proceeded to assert his claims to be regarded as its first inventor. Many meetings took place on the subject, and much discussion ensued, the result of which was that a sum of £2000 was presented to Sir Humphry Davy as "the inventor of the safety-lamp;" but, at the same time, a purse of 100 guineas was voted to George Stephenson, in consideration of what he had done in the same direction. This result was, however, very unsatisfactory to Stephenson, as well as to his friends; and Mr. Brandling, of Gosforth, suggested to him that, the subject being now fairly before the public, he should publish a statement of the facts on which his claim was founded.