Schlieffen yearned for more troops at the decisive point, the right wing of the great wheel though Belgium and northern France: "Still greater forces must be raised... Eight army corps must be raised... We continue to boast of the density of our population, of the great manpower at our disposal; but these masses are now trained or armed to the full number of men they could yield... the eight army corps are most needed on or behind the right wing." Schlieffen urges the creation of these eight corps, an addition of a full quarter to the strength of the army, from the reserves, the Ersatz (untrained contingents) and Landwehr (over-age reservists), even though he apparently shared his brother generals' fear of enlarging the army through the enlistment of unreliable elements. The note of desperation grows stronger: "How many [of the eight corps] can be transported [to the right wing] depends on the capacity of the railways... [they] are needed for the envelopment of Paris... How they advance and the attack on the position are shown on Map 3."
It is at this point that a careful reader of the Great Memorandum recognises a plan falling apart: Map 3 in no way shows how the new corps are to advance or to invest Paris, the central strongpoint of the "great fortress" that was Schlieffen's France. The corps simply appear, with no indication of how they have reached Paris. The "capacity of the railways" is irrelevant; railways, in Schlieffen's plan, were to carry the attackers no further than the German frontier with Belgium and France. Thereafre it was the road network that led forward, and the plodding boots of the infantry that would measure out the speed of advance. Schlieffen himself reckoned that to be only twelve miles a day. In the crisis of August and September 1914, German French, and British units would all exceed that, sometimes day after day-the 1st Gloucestershire Regiment averaged sixteen-and-a-half miles during the great retreat from Mons to the Marne, 24 August-5 September, and covered twenty-three and twenty-one miles on 27 and 28 August respectively-but Schlieffen's mean was not far short of the mark. Von Kluck's army on the out wing of the great wheel achieved a little over thirteen miles a day between 18 August and 5 September 1914, over a distance of 260 miles. For the "eight new corps," needed by SChlieffen as his plan's clinching device, to arrive at the decisive place of action, they would have actually needed to march not only farther and faster, which defied probabilities, but to do so along the same roads as those occupied by the corps already existing, a simple impossibility.
It is not surprising, therefore, to find buried in the text of the Great Memorandum its author's admission that "we are too weak" to bring the plan to a conclusion and, in a later amendment, "on such an extended line we shall still need greater forces than we have so far estimated." He had run into a logical impasse. Railways would position the troops for his great wheel; the Belgian and French roads would allow them to reach the outskirts of Paris in the sixth week from mobilisation day; but they would not arrive in the strength necessary to win a decisive battle unless they were accompanied by eight corps-200,000 men-for which there was no room. His plan for a lightning victory was flawed at its heart.