(22.) Ovens can be easily improvised, the main object being to obtain a covered-in space which will bear and retain the heat of a fire lighted inside. In a clay soil they can be dug out.
(23.) When using a field kitchen, a simple plan is to dig the transverse trench about 12 inches deeper in the part selected for the oven, then take the handle from the pick and drive it into the ground, measuring the distance from the edge of the trench, according to the length of the oven required, then dig out the soil or clay, leaving a portion for the roof about 8 inches deep, but this depends upon the ground. When the oven is sufficiently large, care being taken that it is not more than 12 inches high, the pick handle should be drawn out; the hole will then act as a flue. The fire should be lighted, and the oven allowed to become thoroughly hot before the dishes are placed in. A piece of turf large enough to cover the front of the oven should have been cut, which will act as the door, pugging it round as with the Aldershot oven.
(24.) Beer or biscuit barrels make excellent ovens, one end is knocked out, the ground slightly sloped, so that it may rest firmly, the sides, back, and top being covered with clay, as directed before, well wedged downwards, to become quite hard; the fire is then lit and allowed to burn until the whole of the barrel is consumed; the hoops will then support the clay, and the oven may be safely used. Where the clay is good a small oven may be built by it alone. Build two walls the required distance apart, about 6 inches high, with clay that has been well beaten and mixed, the back being joined to the walls; then, with one hand on either side, gradually build the walls a few inches higher, the tops slightly sloping towards each other, leaving an interval in the form of a V in the centre, then mould a piece of the clay large enough to fill the space, and place it in, care being taken to well join the edges with the walls both inside and out; a small fire should then he lit and allowed to burn slowly till the clay is dry, it will then become baked and quite firm, and may be used as other ovens.
(25.) Tin biscuit boxes are also a good substitute for an oven. Melt one side of the solder, and form it into an oval shape, lay it on the ground, and cover with a few inches of clay or soil sufficient to retain the heat; light the fire, and proceed as with others.
(26.) Small joints of meat may be baked in the service camp kettle. When using a pegged trench a small amount of fat should be placed in the bottom, then a few clean pebbles large enough to cover the fat, the joint placed on the pebbles, and the lid put on. It requires a little longer to cook than the ordinary oven, and it is hardly possible to perceive any difference in the taste. Ant heaps are extensively used as ovens, the insides being scooped out and the fire lighted as in an ordinary oven.