Thus the Russians landed three corps of 20,000 each where they were least expected, and at once prepared to invest Edinburgh and Glasgow. Three of the boats which came ashore at Leith that night, after the blowing up of the fort, brought several large mysterious-looking black boxes, which were handled with infinite care by the specially selected detachment of men who had been told off to take charge of them. Upon the locks were the official seals of the Russian War Office; and even the men themselves, unaware of their contents, looked upon them with a certain amount of suspicion, handling them very gingerly, and placing them in waggons which they seized from a builder's yard on the outskirts of the town. The officers alone knew the character of these mysterious consignments, and as they superintended the landing, whispered together excitedly. The news of the invasion, already telegraphed throughout Scotland from end to end, caused the utmost alarm; but had the people known what those black boxes, the secret of which was so carefully guarded, contained, they would have been dismayed and appalled. Truth to tell, the Russians were about to try a method of wholesale and awful destruction, which, although vaguely suggested in time of peace, had never yet been tested in the field. If successful, they knew it would cause death and desolation over an inconceivably wide area, and prove at once a most extraordinary and startling development of modern warfare. The faces of a whole army, however brave, would blanch before its terrific power, and war in every branch, on land and on sea, would become revolutionised. But the boxes remained locked and guarded. The secret was to be kept until the morrow, when the first trial was ordered to be made, and the officers in charge expressed an opinion between themselves that a blow would then be struck that would at once startle and terrify the whole world. CHAPTER XXX. ATTACK ON EDINBURGH. In attacking Edinburgh the besiegers at once discovered they had a much more difficult task than they had anticipated. The Russian onslaught had been carefully planned. Landing just before dawn, the 1st Corps, consisting of about twenty thousand men, marched direct to Glasgow by way of South Queensferry and Kirkliston, and through Linlithgow, sacking and burning all three towns in the advance. The 3rd Army Corps succeeded, after some very sharp skirmishing, in occupying the Pentland Hills, in order to protect the flanks of the first force, while a strong detachment was left behind to guard the base at Leith. The 2nd Corps meanwhile marched direct upon Edinburgh. The defenders, consisting of Militia, Infantry, Artillery, the local Volunteers left behind during the mobilisation, and a large number of civilians from the neighbouring towns, who had hastily armed on hearing the alarming news, were quickly massed in three divisions on the Lammermuir Hills, along the hills near Peebles, and on Tinto Hill, near Lanark.