them to give away the slide to Pembroke, and had they taken to slides even for the last few days they would probably have also won the Grand Challenge. As it was, that prize fell to the L.R.C., a crew which had four good men, and then a weak tail. The sliding seat had now fairly established its claims. It should be added that Pembroke, with two good and two moderate men, won the Visitors' Plate from a very good Dublin four, about the best four that Dublin ever sent to Henley. Pembroke used slides, and the Dublin men had fixed seats. (Slides alone won this race for Pembroke.) The Pembroke slides were on wheels--a mechanism which was soon afterwards discarded by builders in favour of greased glass or steel grooves or tubes, but which seems to be returning to favour in 1886 and 1887. II. THEIR USE. In order to understand the true action in a slide, it will be well to recall the action of fixed-seat rowing. On the fixed seat the swing of the body does the main work, being supported by the legs, which are rigid and bent. On a slide the legs extend gradually, while at the same time they support the body. On a fixed seat the body moves as the radius of a circle that is stationary; on a slide the body moves as the radius of a circle which is itself in motion. Suppose a threepenny-piece and a half-crown placed alongside of each other, concentrically, with a common pivot. Let the threepenny-piece roll for a certain distance on the edge of a card. Then any point in the circumference of the half-crown will move through a curve called a 'trochoid.' This is practically the sort of curve described by the head or shoulders of an oarsman who rows upon a sliding seat. The actual gain of rowing power by means of this mechanism is considerable. The exact extent of it is not easy to arrive at, there being various factors to be taken into consideration. In the first place, the length of reach, or of the 'stroke,' is considerably increased. Mr. Brickwood in 1873 conducted some scientific experiments on dry land upon this subject, in conjunction with the editor of the 'Field' and Mr. F. Gulston. The result of these measurements was to demonstrate (in the person of Mr. F. Gulston) a gain of about 18 inches in length of stroke upon a 9-inch slide. In 1881 some casual experiments of a similar sort were conducted on a lawn at Marlow by the Oxford crew then training there. The writer was present, and, so far as he remembers, the results practically confirmed the estimate of Mr. Brickwood above recorded, allowance being made for the fact that the gentleman by means of whose body the ideal stroke was measured at Marlow was longer-bodied and longer in the leg than Mr. Gulston.