=168.= Where the space between tables is very restricted the chairs should be fastened to the floor, so that there can be no blocking of gangways. One plan is that adopted at the Mitchell Library, Glasgow, North Library, Fulham, and elsewhere, of having revolving arm-chairs mounted on pedestals secured to the floor. These have the one great disadvantage of being non-adjustable. Readers cannot pull them a little forward or push them back, and thus such fixed chairs have the defect of all fixed things--they cannot be moved to suit varying conditions. Another form for a crowded situation is a small strong chair of good design anchored to the floor by means of a stout cord (Fig. 54). Each chair has a stout staple screwed under the seat in the centre, and a similar staple is screwed into the floor at a suitable distance from the table front, and corresponding in situation with the staple in the chair seat when placed in position. Lengths of stout window cord are then cut and provided with swivel hooks at either end, which are fastened to the staples on the floor and on the seat, allowing a sufficient length of cord to admit of a fair amount of play and movement when anchored. On granolithic or other cement or concrete floors, fixed chairs cannot be used readily. This kind of anchorage allows of a chair being moved backwards, forwards or sideways, and readers can get to and from their seats without trouble. Arm-chairs are not recommended for this style of fastening. All kinds of chairs should be shod with rubber or leather pads to deaden the noise of movement on the floor. There are several varieties of such pads to be obtained from furnishing firms. [Illustration: FIG. 54.--Chair with Anchorage Attachment (Section 168).] =169.= Hat rails of metal or wood are sometimes provided under all chairs--a very necessary provision in wet weather. The Continental system of uncovering the head when entering public buildings is not yet very common in the United Kingdom, but readers should certainly be encouraged to do so by having the means of bestowing their headgear placed easily at hand. General hat, coat and umbrella stands or racks are not popular in public libraries, and need not, as a rule, be provided. But some kind of hat and umbrella holders should certainly be provided in connexion with the chairs. A very good combination arm-chair is shown in the accompanying illustration (Fig. 55). This provides hat and umbrella accommodation, and may also have attached to the left, or both arms, a folding wire-work drop holder, in which to place completed papers, light books or other articles not wanted to litter the table-top (Fig. 56). Of course, such chairs with these additional accessories could only be used in situations where there was plenty of room. In many cases umbrella rails are attached to every table, and this is usually the best plan.