We next turn our attention to Convenience in Use. Under this head the armourer had to consider that the human body makes certain movements of the limbs for walking and riding, or fighting with arm and hand. He had so to construct the different portions of the suit that they should allow of all these movements without hindrance; and at the same time he had to endeavour to protect the body and limbs while the movements were taking place. The arrangements for pivoting elbow- and knee-joints need scarcely be detailed; for it will be seen by a glance at any suit of plate armour how the cuisse and jamb are pivoted on to the genouillière, and move with the leg to a straight or bent position without allowing these plates to escape from under the genouillière. The coude is sometimes pivoted in the same manner, but more often it is rigid and of such circumference that the arm can bend within it and yet be very adequately protected. In the overlapping lames or strips of metal which give ease of movement to the upper arm, the hands, the waist, and the foot, we find that much careful work and calculation was needed to ensure comfort to the wearer. On the foot, the toepiece and four or more arches of metal overlap upwards on to a broader arch, while above this three or more arches overlap downwards, thus allowing the toe-joint and ankle to be bent at the same time (Fig. 26). In a suit in the Tower, made for Prince Henry, son of James I, all the arches of the soleret overlap downwards. This points to a certain decadence in the craftsmanship of the armourer of the period, though the excuse might be offered for him that the suit was intended only for use on horseback. There are generally one, two, or more of these movable lames joining the genouillière to the jamb, and above this the cuisse to the genouillière to give greater flexibility to the knee fastenings. The separate arm- and leg-pieces are, when made in two halves to encircle the limb, hinged on the outside and closed with strap and buckle, or with locking hook or bolt on the inside. This, of course, is to ensure greater protection to these fastenings, especially on horseback. Higher up again we get the tuilles or taces, which, from the fact that to adapt themselves to the human form they must narrow at the waist and spread out below, overlap upwards. From the taces are hung the tassets, with strap and buckle, which give increased protection to the upper leg, and yet are not in any way rigid. When the tassets are made of more than one plate they are attached to each other by a most ingenious arrangement of straps and sliding rivets. On the inner edge of each plate the rivets are attached to a strap on the under side; but the outer edge, requiring more compression of the lames together, is furnished with rivets fixed firmly in the uppermost plate and working loose in a slot in the back plate, thus allowing an expansion or contraction of half an inch or more to each lame.