The uncertainty which has prevailed during the last few days respecting the course which our Government would pursue, in view of the difference respecting the Congress which had arisen between ourselves and Russia, has received a startling and momentous solution. When the House of Lords met yesterday, Lord Derby no longer occupied his seat on the Ministerial Bench, and he at once announced that he had resigned the office of Secretary of State for Foreign Affairs.... The explanations given yesterday remove all doubt respecting the relative positions assumed by our Government and Russia in regard to the Congress. Sir Stafford Northcote stated in the House of Commons the import of the communications which have passed between ourselves and Russia.... Russia's reply amounted to a clear intimation that she claims to withhold from the cognizance of the Powers any articles of the preliminary Treaty she may choose. Such a reserve as she asserts is tantamount to a definite claim to alter an existing Treaty by force of arms without consulting the other Powers who signed it, and towards whom she is under honourable obligations. There being this imminent danger that the Congress may not meet--it being, as Lord Beaconsfield said, "the belief" of the Government "that the Congress would not meet," it became necessary for the Government to consider what further course they would take.... We do not know what course Lord Derby would have advised, and it is possible he would not immediately have taken any fresh steps. But the rest of the Government decided that in the interests of peace, and for the due protection of the rights of the Empire, it was their duty "to advise Her Majesty to avail herself of those powers which she has for calling for the services of her Reserved Forces." As subsequently explained by Mr. Hardy in the House of Commons, this step is one which is rendered necessary by the new organization of the Army.... Its result will be to raise our regular forces to their utmost efficiency. In other words, it will place the land forces which actually exist in readiness for prompt action; and it is thus a plain declaration--a declaration rendered emphatic by Lord Derby's resignation--that we are prepared to act promptly if the course on which Russia has entered directly injures our honour or our interests. Such a declaration of our being determined to adhere to the claims we have put forward is perhaps the most momentous step which has yet been taken by this country. PEACE WITH HONOUR (1878). =Source.=--_The Times_, July 17.