LONDON, Nov. 29.--A report from Field Marshal Sir John French covering the period of the battle in Flanders and the days immediately preceding it, issued today by the Official Press Bureau, shows that this battle was brought about, first, by the Allies' attempts to outflank the Germans, who countered, and then by the Allies' plans to move to the northeast to Ghent and Bruges, which also failed. After this the German offensive began, with the French coast ports as the objective, but this movement, like those of the Allies, met with failure. The Field Marshal, doubtless in response to the demands of the British public, tells what the various units of the expeditionary force have been doing--those that failed and were cut off and those who against superior numbers held the trenches for a month. He gives it as his opinion that the German losses have been thrice as great as those of the Allies, and speaks optimistically of the future. The report covers in a general way the activities of the British troops from Oct. 11 to Nov. 20. Summing up the situation in concluding his report, the Field Marshal says: "As I close this dispatch, signs are in evidence that we are possibly in the last stages of the battle from Ypres to Armentieres. For several days past the artillery fire of the enemy has slackened considerably, and his infantry attacks have practically ceased." Discussing the general military situation of the Allies, as it appears to him at the time of writing, Sir John says: "It does not seem to be clearly understood that the operations in which we have been engaged embrace nearly all of the central part of the Continent of Europe, from the east to the west. The combined French, Belgian, and British Armies in the west and the Russian Army in the east are opposed to the united forces of Germany and Austria, acting as combined armies between us. "Our enemies elected at the commencement of the war to throw the weight of their forces against our armies in the west and to detach only a comparatively weak force, composed of very few of the first line troops and several corps of second and third line troops, to stem the Russian advance until the western forces could be defeated and overwhelmed. Their strength enabled them from the outset to throw greatly superior forces against us in the west. This precludes the possibility of our taking vigorous offensive action except when miscalculations and mistakes are made by their commanders, opening up special opportunities for successful attacks and pursuit.