=166. Reading Easels.=--In connexion with these special tables, book-stands or easels for keeping a number of books open at once will be found useful. It often happens that a student desires to compare his authorities, and an easy means of keeping several books open at a given place is necessary. The book easels shown below are the best form yet devised. Fig. 52, which is made entirely of metal, has the advantage of leaving the table surface practically free and unobstructed, while the automatic means provided for keeping books open at any place, irrespective of the number of leaves, is of great utility. [Illustration: FIG. 50.--Rack for Odd or Occasional Periodicals, Finsbury Public Library (Section 165).] Fig. 53, constructed of wood, is also a light useful article, but as it rests the book close to the table surface more obstruction is caused, while the leaf-holders are not automatically adjusting. There are various other forms of wooden reading easels, but they are light articles designed to fold up, and will not carry large reference books with any great degree of security. =167. Chairs.=--There is such an immense variety of library chairs that the chief difficulty becomes that of selection. A strong chair with a saddle seat fixed to a special rail instead of direct to the legs is best, and in all ordinary situations arm-chairs are preferable, as they give an automatic spacing of elbow-room which renders calculation unnecessary. It is wise, however, to avoid a very wide arm-chair, and to use small chairs only if space is limited to two feet per reader. [Illustration: FIG. 51.--Railway Time-table Rack (Section 165).] [Illustration: FIG. 52.--Metal Reading Easel (Section 166).] [Illustration: FIG. 53.--Wooden Reading Easel (Section 166).]