The Seed of Empire by Fred M. White

The danger was even greater than the troops in the trenches anticipated, for this time the Germans were not hurrying matters. They had learnt a lesson from the wild dash on Paris, and had gained a wholesome respect for the striking power of the British army. But they had the men ready, which in those early days could not have been said of either the English or French, and it was only a matter of collecting them together, sufficiently supported with the requisite artillery and, cavalry, though so far the latter arm of the German service had not played a brilliant part in the campaign.

It was the French who gave their Allies the first intimation of the great coming strife and incidentally conveyed to Paris and London certain news that sent a chill down the spine of the authorities.