No. 3.  Flax.  Weight of 20 yards, 44 oz.  Advantages—­When dry, is softer, more pliable, and easier to handle than 1 and 2, and will probably wear better than 1.  Disadvantages—­When wet, becomes decidedly somewhat weaker, and is nearly as disagreeable to handle as 2.

Knots.—­There can be no doubt that every knot in a rope weakens its power of resisting a sudden jerking strain.  How great a loss of strength results from a knot we cannot undertake to estimate, but that the loss is a very serious one the following statement will show:  these ropes which we report will resist the strain of fourteen stone falling eight feet, will not resist it if there is a knot in any one of them; or even if the knots used in attaching them to the point of support, or to the weights, be roughly or carelessly made.  The rope in these cases breaks at the knot, for two reasons; partly because of the folds, as they cross in the knot, are strained suddenly across each other, and one of them is cut through; and partly because the rope is so sharply bent that the outer side of each fold in the knot is much more stretched than the inner side, so that the strain comes almost entirely upon one side only of each fold.  For the first reason, we found it necessary to put a pad of some kind inside the knot—­leather, linen, or a little tow or waste rope will do.  For the second reason we preferred knots in which the folds are least sharply bent round each other; that is, in which the curves are large.  We therefore conclude that—­1st.  No knot, which is not absolutely necessary, ought to be allowed to remain on the rope:  2nd.  The tighter and harder a knot becomes, the worse it is:  3rd.  The more loose and open a knot is made, the better it is:—­and we append diagrams of those knots which we found by experiment weaken the rope least.  For Alpine ropes, only three sorts of knots are ever required, and we suggest one of each kind:—­No. 1 is for the purpose of joining two ends.  No. 2 is for the purpose of making a loop at one end.  No. 3 is for the purpose of making a loop in the middle when the ends are fastened.  No. 4 is a knot, of which we give a diagram in order that no one may imitate it.  It is one of those which most weaken the rope.  The only one which seemed to be equally injurious is the common single knot, of which no diagram is necessary.  As the topes which we have recommended are very liable to become untwisted, unless the loose ends are secured, we advise travellers, in order to avoid knots, to have the ends of every piece of rope bound with waxed twine.  It should also be known that it is very unsafe to join two pieces of rope by looping one end through the other, so that when the jerk comes, they will be strained across each other as two links of a chain are strained across each other.  Unless a pad of some kind divides the loops, one will cut the other through.

[Four diagrams of knots on this page].