formed in advance as to changes of speed in so far as these can be foreseen, and to let him know how long a given condition will probably continue. If stopped or running slow this may save "blowing-off." It will also enable him to prepare for keeping position when "standard" speed is again called for.

It must be remembered that the Rules of the Road do not apply to vessels running at night without lights. A fleet running in this way must therefore keep clear of all vessels carry ing lights.

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Generally speaking, the longer and heavier the tow-line used, the easier the towing will be. A decided dip or catenary " gives the same advantage here as in the case of a vessel riding at anchor with a good scope of chain;—that is to say, the sagging bight acts as an elastic spring, preventing variations in the tension from being thrown upon the line in sudden jerks; and the sag of the bight depends not only on its length but on its weight. Unfortunately, however, too great weight is a serious inconvenience in handling and running lines. This is the principal objection to chain-cable, which in many ways is an ideal tow-line. Another objection is that if the vessels are obliged to stop, the weight of the chain may prove sufficient to drag them into collision. In the excellent work on Seamanship by Captains Todd and Whall, the use of chain-cable (alone) is recommended for all cases of heavy towing; one of the authors testifying to its availability as the result of his own experience upon several occasions. This is high authority, but the present author has collected the views of more than forty prominent shipmasters, every one of whom says that under no circumstances would he attempt to tow by chain alone, unless compelled to do so.

Wire-rope is very convenient for handling, and makes an excellent tow-line for smooth water, but is much too light to give a satisfactory spring for all-around work under ordinary conditions. All of its advantages may be realized and its disadvantages eliminated, by the use of a Towing Engine, which sub

1 Observe that the dip does not in the least reduce the tension of steady towing. What it does is to furnish an elastic link between the ships, by which the forces already described as arising in a seaway are absorbed gradually instead of being thrown upon the line with the suddenness and disastrous effect of "impact."

stitutes the elasticity of steam pressure for that due to a long and heavy line. This will be referred to at greater length hereafter.

Both chain and wire have a serious disadvantage in that they are not buoyant, as are lines made from vegetable fiber.

Manila and Coir, while heavy enough to give a good dip if used in sufficient length, are not too heavy for convenient handling, and their buoyancy is a great advantage, particularly where lines are to be run by boats or hauled across over considerable distances. Manila, although much less buoyant than coir, is very much stronger and is probably upon the whole the most satisfactory line that can be used for moderate towing; but although heavier than wire of corresponding strength, it is still much too light for towing in a seaway. Its weight is increased in some cases by hanging a good sized kędge to the bight between the two ships;—a device which is evidently available with wire, as well as with manila. A more common plan is to use a combination of chain-cable with a manila or wire hawser, or both, the hawser being made fast to the towing ship and the chain-cable paid out by the tow.

When the conditions for getting the lines across from one ship to the other are fairly good, a combination of wire and chain is perhaps the best; but in bad weather, or when, for any reason, the ships cannot come close together for running the lines, the buoyancy of manila—its “floatability”—shows up as an enormous advantage, especially where the vessel which is to receive the line, get it on board, and secure it, is a small craft, such as a torpedoboat or destroyer. The use of a manila hauling line helps out, but cannot do away with the difficulties connected with dragging a wire-line across a long stretch of water and securing it on the cramped forecastle of a small vessel which is perhaps plunging into a heavy sea. A good plan here is to combine manila and wire, the towing vessel first paying out the manila line, which is hauled across by the tow and secured, after which the towing ship shackles the wire-line to the manila and starts ahead very slowly, paying out the wire-line as she gathers way.

For towing a destroyer in rough weather-and it must not be forgotten that rough weather may be encountered in almost any

towing expedition—the full length of an 8-inch or 10-inch manila line with the added length of a 5-inch or 6-inch wire, will be none too much.

Where the tow is able to haul across and handle a wire-line, and especially where she proposes to use with it a good length of her own bower-cable, a 6-inch or 7-inch wire-line is recommended. The length that is needed will vary with circumstances, but it is far better to have too much than too little; and the use of a margin of safety which seems unreasonably large may result in a very comfortable security from the vexatious accidents and delays which are so common in towing.

Where a battleship is to be towed, the full length of a special 7-inch wire-line (200 fathoms) is recommended, in addition to 75 or 90 fathoms of bower-cable. With such a line there should be no troublesome break-downs unless the speed is forced unduly. (See remarks below on Speed and Resistance.")

Securing on the Towing Ship. In securing the line, consideration must be given to the possible necessity for letting go in a hurry. It is clear that there are many emergencies which may arise in which the line must be gotten rid of in the shortest possible time; such as a sudden threat of collision. This is a point which is not always given the consideration to which its importance entitles it.

For convenience in letting go, it is desirable to have a break in the line near the stern; that is to say, to have, at or near this point, a shackle connecting two parts of the line, together with some arrangement, like a pelican-hook, for slipping quickly.

The objection to letting go at any point well inboard of the ship is that a dangerous "whip" is certain to result as the end of the line goes out.

To have the end only just inside the stern-chock on the towing ship means that practically the whole length of the tow-line must be paid out, and that any variation in length must be taken care of by the tow. As it happens, this is usually the simplest way to arrange matters, provided the bower cable of the tow is in use as a part of the line, as it almost always is. It is very easy to heave in or veer away on this, as may be necessary for shortening or lengthening the line.