Rook-hawks which have been brought out to fly, but are not for the time actually engaged, either because their turn has not come, or because they have already flown and been fed up, are either carried about by a cadger on the cadge, or made fast to a field-block in a well-sheltered place, or consigned to perches rigged up in the inside of a van, which can be drawn by a cart-horse. The latter plan is adopted by the Old Hawking Club, by which more hawks are usually taken out than could be accommodated on one cadge. It has the great merit of serving to protect the inmates from the bitterly cold winds which often prevail in the rook-hawking season, and also from the rain. Such a van should be well provided with springs. Otherwise the jolting, while it passes over rough ground, as it needs must, would do almost more mischief than the wind or rain. In any case, whether you go singly with a single hawk on your fist or with a whole cadge full or van full of hungry peregrines, the hood will be worn. Nor will it be removed until the moment arrives when the wearer is to be thrown off. But when any hawk is being carried with a view to a flight the swivel will be detached from the jesses and the latter held tightly in the fingers of the left hand. Some falconers who use ring swivels in the field, take them off directly the hawk is taken on the fist for the purpose of being flown, and then slipping the leash through one ring of the swivel and afterwards through the loops in the two jesses, are ready to pull it out quickly when there is a rook in sight and it becomes possible that they may have to throw off at any moment. Some also, when a flight is pretty sure to begin shortly, loosen the hood's braces without taking it off, so that there may be no delay in whipping it off at exactly the right moment. No one has ever been able to explain how it is that peregrines can emerge suddenly from utter darkness into the full glare of daylight, with eyesight as good as ever, ready in the very first moment to catch sight of a distant rook and to begin the chase. That they have this faculty everyone knows who has ever seen a rook flown by a trained peregrine. Fortunate for the falconer that it is so, as he can choose his own moment for the throw-off.