PROBABLY the most ancient mode of propelling boats through the water by hand labour was by means of oars of nearly the same shape, and worked in the same manner, as those now in use. And to all appearance there is no likelihood of a change, for although many savage tribes work their canoes and other narrow boats with hand-paddles, and attain great speed with them, yet seamen of civilized nations, whose boats are mostly of a more burdensome character, and whose bodies are encumbered with clothing, have, without exception, given preference to the oar, as an instrument of greater power, and worked with more convenience.

And, truly, there is no more beautiful instrument than an oar, when we consider its simplicity, the ease with which it is worked, and the readiness with which its position is accommodated to the ever-varying motion of the boat and the sea's surface.

It has often been proposed—indeed, it is a favourite notion with theorists—to propel life-boats by rotatory paddle-wheels and screws, such as those of steamers; but the proposition is altogether an impracticable one, and its trial could only result in failure.

Where great power and velocity of motion can be applied, as by steam, undoubtedly the rotatory form is the most convenient mode through which to apply it, and accordingly, both screws and paddle-wheels work advantageously, until the rolling or pitching motion of a ship becomes very violent, when great waste of power ensues; for instance, when a ship rolls so deeply that the paddles are alternately too deeply immersed, and spinning round in the air; or if a screw ship, when she pitches so much that the screw is raised to the water's surface, or lifted above it. When, therefore, it is considered how much more violent is the motion of a boat in a heavy broken sea than that of a ship, it will be readily conceived that a fixed machine, such as a wheel or screw, even if it could be worked on so small a scale by steam power, would do so at a still greater disadvantage.

Whereas the oar, obedient to the quick eye and ready arm, varies its position with every motion of the boat or wave, and in skilful hands is always working at " full power." But there is another point of importance not to be lost sight of. A paddle-wheel or screw cannot be worked in a life-boat by steam power, but must be so by means of a crank worked by hand. Now it is known to every one that the muscles of the human body are strengthened by use, and that, therefore, persons engaged on any particular bodily labour have those muscles especially strengthened that-are constantly brought into play. Thus, a sailor would stand little chance in a walking-match with a professional pedestrian; whilst the latter would as vainly attempt to overtake the former in a race over his ship's mast-head.

It follows then, that, apart from its other advantages, the oar is possessed of this especial one, that it is in daily use by the only class of men on the coasts who are available to form the life-boat's crew, viz., the hardy race of fishermen and boatmen who earn their daily bread on our shores.

An oar being, then, the only instrument by which a life-boat can be propelled, too much care cannot be bestowed on it. Its size, weight, length, material, width of blade, balance, mode of attachment to the gunwale; its height above the water, and above the thwart on which the rower is seated, and the distance of the thwarts and oars apart, are all points of much importance on which the speed of the boat, or its power to make way against a headsea, much depend.

An oar is a simple lever, of what is termed the second order, that is, wherein the weight or body to be moved lies between the fulcrum and the motive power; the water being the fulcrum of the lever, the gunwale of the boat the point at which its power is applied to the moving body or weight, and the rowers' arms being the source of power.

Fir oars have always been considered the most desirable for life-boats, as they do not bend so much as ash oars, and as they float much lighter in the water, and will therefore better support any persons in it in the event of accident. Experiments have been made by the NATIONAL LIFE-BOAT INSTITUTION to test the relative strength of oars, when it was ascertained that an oar made from a good white Norway batten, or from a white Baltic spar, will bear as great a strain as any other, each being as free of knots as possible.

The length of an oar must of course be proportional to the width of the boat, and it should be so poised on the gunwale that the rower can raise or depress it or move it in any direction with the smallest effort. An oar should be not less than five inches wide in the blade, or it will expose so small a surface to the water as to cut through it, and so work on a too yielding fulcrum, with comparative loss of power.

The height above the thwarts, of the thowl or rowlock in which the oar works on the gunwale, should be sufficient to enable the rower to lift the blade well above the waves by depressing the loom or handle; but, on the other hand, it must not be so high as to require him to raise his arms above the level of his chest in rowing, in which case he will row with much less force, and be much sooner fatigued. A height of eight inches from the thwarts to the oar on the gunwale will be found a suitable average.

Lastly, the mode of confining the oar to the gunwale of the boat is of much consequence.

The most common modes, in ordinary boats, are rowlocks and double pins, between which the oar works; but as an oar is liable to jamb in the rowlock or between the pins, when rowing in a rough sea, and thereby to get broken, or to damage the gunwale, the oars of life-boats have generally been worked in a rope grummet or ring, over a single iron thowl-pin: a further advantage of this plan being that it enables the oars to lie along the outside of the boat when not in use, and thus saves the necessity of unshipping them and getting them in-board on going alongside a wreck, which is a great advantage.

A new description of swivel-crutch, intended as a substitute for a grummet, has recently been planned for the National Institution's life-boats, by its inspector, Capt.

WARD, R.N., which is found to have the advantages of the grummet, and to be more convenient in some respects.

As it will be found to be a very useful kind of cratch for general use in boats, we subjoin a sketch of it.

Figure 1 represents the inside of a boat's gunwale, with a section of the oar within the crutch, the latter supported on the gunwale in the position in which it remains whilst the oar is in use. a is an ordinary iron thowl-pin ; 6, the crutch, also of galvanized iron, which revolves round the thowl as an axis; c, a clamp or chock, which receives the lower end of the thowl; d, a section of the oar; e, a short laniard with a running eye, which is slipped over the head of the thowl whenever the oar is required to hang over the side; /', the gunwale.

Figure 2 shows the oar when let go by the rower and allowed to hang alongside outside the gunwale, a, the thowl; b, the crutch; c, the leathering on the oar, to prevent chafe; d, the oar, as hung along- Fig. I.

Fig. 2.

side; e, the laniard spliced round the oar, below the leathering, and nailed on to prevent its slipping round or along the oar; f, the gunwale.

The principal advantage of the swivelcrutches over grummets is, that they are of a more durable character, are fixtures, and so not liable to be mislaid or lost, and retain always the same size and shape, whereas a grummet is liable to stretch by use, when the oar will work too loosely in it.