Neither Brown nor Babcock quite understood the principle of the slide, and both believed that it was merely a mechanical aid to getting the oars man into the best position for the catch and the finish, and the fact that the legs could be made a part of the stroke was not apparent. It was found that the proper control of the slide made rowing very difficult, because a crew had to slide together as well as catch together ; few oarsmen used more than six inches of slide, and the smooth board was often preferred to the sliding seat, which went away too easily and was apt to break the force of the catch. Harrington Putman, a well-known amateur oarsman, wrote in favor of the polished board thus : " To the young oarsman the easy motion of the moving seat has many attractions. For a short distance his work is done with less labor and at a quicker pace ; yet the motion, so pleasant at first, causes too long a slide, which, in the end, only exhausts.
" At the beginning of the stroke the powerful muscles of the legs are in a most favorable posi tion for an advantageous outlay of strength. No sooner does the pressure commence on the stretcher than the tendency of the seat is to slide back on the wires, long before the body and arms are prepared. Thus the very freedom with which the seat moves causes but a small part of the advantage of the sliding motion to be secured. The area of the slide is so limited — usually as small as possible — that it is a disadvantage plainly felt at the finish. Though its surface is perhaps sufficient at the beginning and the middle of the stroke, after the body has passed the perpendicular at the finish, the need of a larger surface on which to sit is plain to all." The victory of the Wards at Saratoga, in 1871, rowing on the board while several of their corn petitors had slides, strengthened the opposition to the slide. But gradually the idea that the legs might be a part of the stroke crept in, and with this idea the slide found more and more followers, until, in a few years, the board had passed out and the modern strokes began to develop. The slides were all short and ran on brass rods on the thwart, or sometimes the seat had runners which fitted into grooves that were lined with brass or glass or zinc, the runners being shod with boxwood or bone. The track was perfectly level, and the oarsman brought himself back by his toe-straps. In 1877 Thomas Farron, the oarsman, fitted wheels to the seat in order to reduce the friction, but the wheels were too large and the seat ran too easily ; smaller wheels were found to be better, and grad ually the present slide with two pairs of small wheels on each side fitted in travellers came into use, and the slide was also pitched toward the stern of the boat in order to facilitate the recov ery. The Englishmen still use the level slide, claiming, with some reason, that no help toward a quick recovery is needed, and that the incline only tends to increase the work in the stroke by forcing the slide uphill.
The early oarsmen and scullers all used the thole-pins, in which there is considerable lost motion, and in 1874, Mike Davis, the professional oarsman and especial boating genius, invented the swivel lock, which, in a couple of years, found ready use on all sculling craft, where the lost motion was felt more than in the rowing boats. Later
the sweeps began to use them, and the swivel, in one form or another, has banished the thole-pin from this country. But, as previously explained, the " thump " of the oar against the thole is of the greatest use in getting a crew together, and the swivel also does not admit of the hard catch that may be had on the firm and unyielding surface of the broad thowl. Even the best swivel will give a little at the catch, and in any stroke where the catch is hard, the thowl, or a swivel with a stationary fulcrum for the oar, is better than the swivel that is now universal. Any oarsman, chang ing from the thole-pins to the swivel Jock, has a feeling of insecurity ; there is much to be said on both sides. The swivels are unquestionably better in sculling boats and pair-oars, but it is an open question in eights and fours.
In the manufacture of oars, there has been as great an improvement as in boats, and the sweep or scull of to-day is a marvel of lightness and strength when compared with the great, clumsy affairs of the old rowers. The theory of an oar is that of a lever: the blade of the oar is to re main as nearly stationary as possible in the water ; the oar-lock is the fulcrum, and thus the boat is forced along. The shape and size of the oar blade is designed to offer the greatest possible resistance to the water consistent with easy han dling; the oarsman does not "pull the blade through the water,"—a frequent expression ; the blade must not move, and its surface must be so great that the water will offer it a sufficient resistance to overcome the power that the oarsman is exert ing, and all the strength of the man will be put into the propulsion of the boat just as though the end of the blade were fastened. Therefore the area of the blade is dependent upon the man who is to wield the oar, while the shape is largely governed by the conditions under which it is to be used ; the area should be no greater than is neces sary. The length and the button or fulcrum are also governed by the convenience and the strength of the oarsman.
The early oars and sculls had no buttons, and were much like the present oars of a fishing-boat with straight blades, and were usually about thir teen feet long, while the sculls ran to eleven feet. The precise time for the introduction of the spoon blade is not known, but it happened somewhere about i85o, and by that time the buttons had also begun to be used. Since then the theories of various oarsmen have resulted in changes in the shape and size ; for a time sweeps were made as short as ten feet with eight-inch blades for use with the quick stroke, but the better men favored a blade around twelve feet with the button at forty-two or forty-three inches. In sculls Hanlan was the first man to use very short sculls, rowing at the Centennial with nine and one-half feet sculls buttoned at two feet eight inches, whereas the other oarsmen had ten-foot sculls with the button at two and one-half feet, regardless of the size. In sweep oars, the present almost universal dimen sions are twelve feet with the button at forty two to forty-four, and the blade seven inches wide. This blade has about the same area as the English six-inch blade, which is longer.