From the Wiki Books, Dr Edmund Warre talking about how to row in 1909:
‘The moment the oar touches the body, drop the hands smartly straight down, then turn the wrists sharply and at once shoot out the hands in a straight line to the front, inclining the body forward from the thigh joints and simultaneously bring up the slide, regulating the time by the swing forward of the body according to the stroke. Let the chest and stomach come well forward, the shoulders be kept back; the inside arm be straightened, the inside wrist a little raised, the oar grasped in the hands, but not pressed upon more than is necessary to maintain the blade in its proper straight line as it goes back and without constricting the muscles of the arms as they go forward; the head kept up, the eyes fixed on the outside shoulder of the man before you. As the body and arms come forward to their full extent, the wrists having been quickly turned, the hands must be raised sharply, and the blade of the oar brought to its full depth at once. At that moment, without the loss of a thousandth part of a second, the whole weight of the body must be thrown on to the oar and the stretcher, by the body springing back, so that the oar may catch hold of the water sharply, and be driven through it by a force unwavering and uniform. As soon as the oar has got hold of the water, and the beginning of the stroke has been effected as described, continuing the movement of the body and the simultaneous use of the muscles of the legs, keep up the pressure of the beginning, uniform through the backward motion of the body. At the beginning of the stroke let the arms be straight. The elbows should not then be bent. When the body reaches the perpendicular, let the elbows be bent and dropped close past the sides to the rear — the shoulders dropping and disclosing the chest to the front; the back, if anything, curved inwards rather than outwards but not strained in any way. The body, in fact, should assume natural upright sitting posture, with the shoulders well thrown back. In this position the oar should come to it and the feather commence.
‘N.B.– It is important to remember that the body should never stop still. In its motion backwards and forwards it should imitate the pendulum of a clock. When it has ceased to go forward it has begun to go back.
‘There are, it will appear, from consideration of the above directions, about 27 distinct points, articuli as it were of the stroke. No one should attempt to coach a crew without striving to obtain a practical insight into their nature and order of succession.
‘Let the Coach also remember that, in teaching men to row, his object should be to economize their strength by using properly their weight. Their weight is always in the boat along with them; their strength, if misapplied, very soon evaporates.’