Because Marlborough and Wellington had such hard fought battles in this region, the military men took it upon themselves, in peacetime, to visit all the battle sites. They regarded this as somewhat of a holiday, and a few years later, a young cavalry officer was glad to hear that Joffre was the Commander in Chief of the Allies and Chief of the British Expeditionary Force (the BEF). In 1914, that young officer was Sir John French.
There had been several German Cavalry attacks, and General French assumed that the enemy had some forces in the Region. Meanwhile, British intelligence had warned him to be cautious because it wasn't known just how big the German presence was. General French then decided to 'dig-in' - in fact the numbers were BEF 70,000 men and 300 Artillery and the Germans had 160,000 men supported by 600 Artillery: this over a 40km front. The firing was so intense, the Germans thought the BEF had at least 28 Machine Guns per Battalion when in fact they only had two per Battalion. The troops were, in fact, using their Lee Enfield Rifles at such a combined speed the Germans were convinced they were mightily outnumbered.
After the War was finished, von Kluck said of the Battle of Mons that the BEF were an "incomparable army".
Xii Brandenburg Grenadiers, attacking the 1st Battalion of the Royal West Kent Regiment lost 25 of their Officers, and more than 500 men; and the 75th Bremen Regiment lost 5 Officers and 376 men in just one attack ; such was the complete devastation meted out by the outnumbered BEF.
Here is a German soldier’s account of the British fire:-
"Well entrenched and completely hidden, the Enemy opened a murderous fire. Casualties were increasing, the rushes became shorter, until finally the whole advance stopped with bloody losses; the attack came to an end."