All yesterday artillery was rolling and troops were marching through Paris on their way to the Porte de Neuilly. The soldiers of the line were worn and ragged; the marching battalions of the National Guards, spick and span in their new uniforms. All seemed in good spirits, the soldiers, after the wont of their countrymen, were making jokes with each other, and with everyone else--the National Guards were singing songs. In some instances they were accompanied by their wives and sweethearts, who carried their muskets or clung to their arms. Most of them looked strong, well-built men, and I have no doubt that in three or four months, under a good general, they would make excellent soldiers. In the Champs Elysees, there were large crowds to see them pass. "Pauvres garcons," I heard many girls say, "who knows how many will return!" And it was indeed a sad sight, these honest bourgeois, who ought to be in their shops or at their counters, ill-drilled, unused to war, marching forth with stout hearts, but with little hope of success, to do battle for their native city, against the iron legions which are beleaguering it. They went along the Avenue de la Grande Armee, crossed the bridge of Neuilly over the Seine, and bivouacked for the night in what is called the "Peninsula of Genevilliers." This peninsula is formed by a loop in the Seine. Maps of the environs of Paris must be plentiful in London, and a glance at one will make the topography of to-day's proceedings far clearer than any description. The opening of the loop is hilly, and the hills run along the St. Cloud side of the loop as far as Mont Valerien, and on the other side as far as Rueil. About half a mile from Mont Valerien following the river is St. Cloud; and between St. Cloud and the Park of the same name is Montretout, a redoubt which was commenced by the French, but which, since the siege began, has been held by the Prussians. The enemy's line extends across the loop from Montretout through Garches to La Malmaison. The latter lies just below Rueil, which is a species of neutral village. The troops passed the night in the upper part of the loop. In numbers they were about 90,000, as far as I can ascertain, and they had with them a formidable field artillery. The object of the sortie was a vague idea to push forward, if possible, to Versailles. Most of the generals were opposed to it, and thought that it would be wiser to make frequent sudden attacks on the enemy's lines; but General Public Opinion insisted upon a grand operation; and this anonymous but all powerful General, as usual, carried the day. The plan appears to have been this: one half the army was under General Vinoy, the other half under General Ducrot. The former was to attack Montretout and Garches, the latter was to push forward through Rueil and La Malmaison, carry the heights of La Jonchere, and then unite with Vinoy at Garches. General Trochu, from an observatory in Mont Valerien, commanded the whole movement.