A separate section deals with objectives, and contains 45 illustrations, giving special attention to: single achromatic (landscape) lens, including aplanatic; unsymmetrical doublets; symmetrical doublets; triple combinations; anastigmatic combinations; telephotographic objectives; anachromatic lenses; diaphragm apertures.

Then follows a discussion of instantaneous shutters (with 9 illustrations) and a discussion under “lateral” and “central” of flap, drop, drop and flap, rotary, roller blind, focal plane, moving blade, central and iris shutters.

Exposure meters (4 illustrations) with a discussion of the actinic power of light; sensitive plates, films and papers: sensitive dry plates, plates for colour photography, celluloid films, photographic printing papers, apparatus for development (with 4 illustrations); photographic printing apparatus; bibliography.

The last division of this great article is on Pictorial Photography, and this is illustrated by three full-page plates. It deals not merely with portrait photography but with “artistic” landscape work, and combination printing, which “is really what many of us practiced in the nursery, that is, cutting out figures and pasting them into white spaces left for that purpose in the picture book.”

In addition to this comprehensive treatise, in itself a complete manual of photography, there are other articles which will be useful to the advanced amateur who desires either to study the scientific aspects of the subject or to undertake the reproduction of his work by processes other than the ordinary printing. The production of chemical changes by the action of light are discussed in Photochemistry (Vol. 21, p. 484). Lens (Vol. 16, p. 421) is by Dr. Otto Henker, of the staff of the Zeiss factory at Jena, Germany. Aberration (Vol. 1, p. 54) is by Dr. Eppenstein, another expert of the same establishment. The making of blocks from your own negatives is covered by the article Process (Vol. 22, p. 408), by Edwin Bale, art director of Cassell & Co., and contains coloured plates showing the stages of superimposed printing. Sun Copying (Vol. 26, p. 93), by F. Vincent Brooks, a practical printer, describes direct-contact printing without the use of a camera.

OUT-DOOR GAMES

The authority which is back of the articles in the Britannica and the fact that its articles are on a larger scale than those of other works of reference make its articles on sports and games singularly valuable. The reader who is interested in Football, for instance, will find an article (Vol. 10, p. 617), of more than 12,000 words, part of it written by Walter Camp, the famous American expert. It includes a historical sketch; a description of the Rugby Union game by Charles James Nicol Fleming, inspector in the Scotch Education Department, and Charles John Bruce Marriott, secretary of the Rugby Football Union; of the Association game, by Charles William Alcock, late secretary of the Football Association, London, and Frederick Joseph Wall, secretary of the Football Association; and of the game in the United States, by Walter Camp and Edward Breck. The article Golf is by H. G. Hutchinson, amateur golf champion in 1886–87, and author of Golf, Book of Golf and Golfers, etc. In the same way there are authoritative and full articles on the following subjects:

And among active indoor games on which the Britannica contains articles, are Fencing, Cane Fencing, Epée-de-Combat, Foil-Fencing, Sabre-Fencing, Single-Stick, Basket Ball, Badminton, Bowling, Tennis, Stické, Fives, Long Fives, Roller-Skating, Squails, Shuffle-Board, Trapeze, Wrestling.

Athletics