The rook, like other broad-winged birds, often makes much leeway in flying, though there be only a moderate wind. The beak points in one direction, in which the bird is apparently proceeding, but if observed closely it will be found that the real course is somewhat sideways. He is making leeway. So it is that a rook which looks as if coming straight towards you--as if he must inevitably go overhead--passes some distance to one side. He appears slow on the wing, as if to go fast required more energy than he possessed, yet he travels over great distances without the least apparent exertion. When going with the wind he sails high in the air, only flapping his wings sufficiently to maintain balance and steering power. But when working against the wind, if it is a strong gale, his wings are used rapidly, and he comes down near the surface of the ground. He then flies just above the grass, only high enough to escape touching it, and follows the contour of the field. At the hedges he has to rise, and immediately meets the full force of the breeze. It is so powerful sometimes that he cannot overcome it, and his efforts simply lift him in the air, like a kite drawn against the wind. For a few moments he appears stationary, his own impetus and the contending wind balancing each other, and holding him suspended. Then he rises again, but still finding the current too strong, tacks like a ship to port or starboard, and so works aslant into the gale. Shortly afterwards he comes down again, if the field be a large one, and glides forward in the same manner as before, close to the surface. In crossing the lake too, against the wind, he flies within a few feet of the water. During such a gale a rook may often be seen struggling to get over a row of trees, and stationary, though using his wings vigorously, suspended a little way above the topmost branches. Frequently he has to give up the attempt, turn back, and make a detour. Though rooks usually go in flocks, individuals sometimes get separated, and may be seen flying alone on the way to rejoin their friends. A flock of rooks, on rising, occasionally divides into two or more parties. Each section wheels off on its own course, while sometimes a small number of those who chance to be near the centre of the original formation seem at a loss which company to follow, and settle down again on the field. So a dozen or more become separated from the crowd, and presently, when they rise, they too divide; three or four fly one way to join one section, and others take another route. Individuals thus find themselves alone; but that causes them no uneasiness, as they have their well-known places of rendezvous, and have only to fly to certain fields to be sure of meeting their friends, or at most to wait about near the nesting-trees till the rest come.