We are, sir, your obedient humble servants, (Signed) H. CLAY, ALBERT GALLATIN. R. G. Beasley, Esq. &c., &c. PLYMOUTH, 26th April, 1815. SIR, In pursuance of instructions received from Messrs. Clay and Gallatin, I have now the honor to transmit to you the report prepared by Mr. Larpent and myself on behalf of our respective governments, in relation to the unfortunate transactions at Dartmoor Prison of War, on the 6th of the present month. Considering it of much importance that the report, whatever it might be, should go forth under our joint signatures, I have forborne to press some of the points which it involves, as far as otherwise I might have done, and it therefore may not be improper in this letter to enter into some little explanation of such parts of the report. Although it does appear that a part of the prisoners were on that evening in such a state, and under such circumstances, as to have justified, in the view which the commander of the depot could not but take of it, the intervention of the military force, and even in a strict sense, the first use of fire-arms, yet I cannot but express it as my settled opinion, that by conduct a little more temporizing, this dreadful alternative of firing upon unarmed prisoners might have been avoided. Yet as this opinion has been the result of subsequent examination, and after having acquired a knowledge of the comparatively harmless state of the prisoners, it may be but fair to consider, whether in such a moment of confusion and alarm, as that appears to have been, the officer commanding could have fairly estimated his danger, or have measured out with precision the extent and nature of the force necessary to guard against it. But when the firing became general, as it afterwards appears to have done, and caught with electric rapidity from the square to the platforms, there is no plea or shadow of excuse for it, except in the personal exasperation of the soldiery, nor for the more deliberate, and therefore more unjustifiable, firing which took place into three of the prisons, No. 1, 3 and 4, but more particularly into No. 3, after the prisoners had retired into them, and there was no longer any pretence of apprehensions as to their escape. Upon this ground, as you, sir, will perceive by the report, Mr. Larpent and myself had no difference of opinion, and I am fully persuaded that my own regret was not greater than his, at perceiving how hopeless would be the attempt to trace to any individuals of the military these outrageous proceedings.