Bows are made of two patterns, that is to say, square and round, which are used for three kinds of shooting. The square are best for butt shooting for three reasons-first, because they have more back and therefore last longer; secondly, because the arrow lies better against their side, and thirdly, because they shoot straighter and keep their cast longer. A bow should be the same shape for the butt and target shooting. Round bows are also made of two patterns for target and flight shooting.
Those made for target shooting have a broader back than the others, as more arrows are shot at it, for if they had too narrow a back, they would not last. Those made for flight shooting have narrower backs and are the better for it, as the back only makes them slower and more sluggish. Sexmodus speaking to his son Tarquin says-" If you wish your bow to last, its length should be that of two arrows and two small fists." But Sexmodus does not mean this to apply to bows used for flight shooting, as they should only be one hand's breadth, by which one holds them, longer than the said two arrows' lengths, and at the most only two or three arrows a day should be shot from them. And every bow should be stronger in the upper limb than in the lower for three reasons- the first is that one has two fingers under the arrow, and the hand by which it is held should properly be opposite the centre of the bow. The second reason is that all bows, which by their make bend, always shoot in the direction of their weakest limb, so that when the lower limb is the strongest (the arrow), jumps and shoots high, and farther. The third reason is that all men who wish to shoot far, must, to do so with the greatest advantage, shoot with the wind and high ; but all the same, every one does not know this, and you must know that when a bow is strongest in the lower limb, it corrects this fault of itself. And a good bow should be very gradually reduced to within a palms-breadth of the ends, and then reduced to small size. For though the principal spring comes from the ends, it could not be good if it was not strengthened towards the centre. And every good and well made bow should be reduced as much as can safely be done near the horns. For the more tapered and gradually reduced a bow is from the centre to the top and bottom, the greater and sharper spring will it have, and in this there is no harm.