The last scheme I gave you dealt with the taking up of a position when an attack by a weak force was probable within an hour or so of your occupying it, and also with the strengthening of the same position for an expected attack by a stronger force twelve hours later. This one deals with a rearguard action. It is straightforward and plain. The object that troops fighting a rearguard action should have in mind is to keep the enemy at arm’s length, to punish him severely if he is too bold, and at the same time not to compromise their own retreat, unless duty requires them to sacrifice themselves in order to save the main body. I will now set you the problem before I make my own solution too evident by my remarks. It is my intention to add a few more words at the end of this letter, but I do not wish you to look at them until you have written your own solution. PROBLEM 4 The banks of the River Lea are steep, the river is about four feet six inches deep, except near the ford. The bottom is muddy. At the ford it is forty yards broad, in most other places about twenty yards. The fields on either side are firm. The roads shown on the sketch are dry and dusty. The soil is chalky. The depth of the river at the ford is two feet six inches. The date is June 20. One of the orderlies attached to you reports that at Slag Farm there is a large quantity of wire, some of it barbed. The brigade to which you belong is retiring in a southerly direction. The baggage moved in front of the brigade. The time is 5.30 p.m. You with your company, to which six mounted orderlies have been attached, are near Home Farm, the remainder of your battalion, which is in rear of the brigade, is passing through Silverton, when the adjutant rides up to you and gives you the following order: “Information has been received that a hostile cavalry brigade is pursuing. You will take such steps as you may consider necessary to prevent the enemy crossing the River Lea between Stone Bridge and Slag Farm, both inclusive, until 7 p.m., at which hour you will be relieved by cavalry. You will be careful not to compromise your own retreat. Having accomplished your task, you will rejoin your unit.” _Problem._ How do you appreciate the situation, and what steps will you take to carry out your instructions? _Solution considered Correct._