On the 7th the artillery fight continued without apparently decisive results on either side, though our retreat continued, as it did on the 8th when the bulk of the Cossacks (about 1,500 men) were at Deutsch Eylau, with orders to fall back on Soldau, a town seventy or eighty versts east of Thorn. There followed a number of movements which I did not understand, and about which I could glean no information. My difficulties were so great that it was not until this day that I learned we were under the direct command of General Rennenkampf, whom I had only seen on one occasion, and then had scarcely more than a glimpse of him. The little I learned with certainty showed that the Russians were obtaining great and important victories over the Austrians, with whom were combined a considerable force of Germans, and that the Prussians were becoming exceedingly nervous about their progress. In consequence, they withdrew a great many units from our front; and the Russians, too, sent a great force to the south, including, I suspect, most of the cavalry that had suddenly departed. Both sides, also, but the Germans principally, began to form extensive systems of entrenchments; and two new devices came into use in modern warfare--viz., hand-grenades and armour breastplates. The grenades were peculiar things, not at all resembling the weapons which gave our Grenadiers their name; of a kind of elongated pear-shape, these were iron cases divided into segments, and attached to a stick which fitted the barrel of a rifle and enabled them to be shot, at an acute angle, into trenches. They were, also, thrown by hand, and were nasty viperish things, often doing a great deal of damage. The shields were a kind of iron breastplate, roughly made, and held in the hand by means of metal handles; so that the men had to drop them when they fired their rifles, or used their bayonets: but afterwards they were attached to the body by means of straps. Except at short range they were bullet-proof. The method of use was for the front rank in a mass of close columns to hold them up, protecting themselves and comrades until they closed with the foe, when they were thrown down that their bearers might use the bayonet. Hundreds of them were taken by the Russians; but the contrivance was too clumsy, and was soon abandoned by both sides. Before the men could drop them and unsling their rifles they were heaps of corpses. The grenades, however, held their own, and were much used in trench warfare.