Twentieth Book
Illustration 453
the hulk and the device (because she will carry a great weight) so she can be removed with greater ease. The following illustration shows how much human understanding can do, since with God's help, we do not lack the industry to devise machines to our purpose. So, if we lack heavy ships for this function, we shalllay our hands on fishing smacks. Note should be taken how much weight each smack can carry by itself: let us take the case where the sunken ship carried two thousand cayzes of wheat, the reckoning made, the smacks have to carry a weight of four thousand. So each ene will need a capacity of 334 cayzes weight; and then the ship under water will be drawn up easily. The smacks are to be so arranged that they all have the points of their prows toward the sunken wreck, sorne on ene side and sorne on the other. [!fol. 449r] Por this task it is very important that the cables should be numerous and stout, with the ends tying atA B (the prows of the smacks are C D), so that the weight will be equal everywhere. It is also desirable to double the ropes if possible because the more folds are given to the ropes the less weight they will cause the cable. Illustration of what has been discussed. (Illustrattón 453) There is another invention too, to raise the ship, without anchors, nor even hooks. A is the smack, BC the beams which cross over the smack, [!fol. 449v] E I the beams which go alongside the smack where cables F H are laid to envelop the ship G. The beam D is ene of those that go between the smacks, to keep them all level and at the (Illustration 454) same distance. At L N the ends of cables K M are attached, and after attaching the ship's sling, give ita turn. Then attach the two ends again at L M. Let them be as taut as the noose can be as it goes next to the beginning O . It then passes under S, at P; then passes again over Q, and at R [611]
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