[3]=194. Photographs.=--Collections of photographs which deal with local matters should be made by every public library (see Chapter XXVIII.). Certain American libraries also collect photographs of great pictures and those which represent various natural forms. Studies for the use of artists are also collected, mounted on cards, and made accessible, and some of these attempts to popularize art should be made in British libraries. Photographs are comparatively cheap, and almost every kind of picture and study can be obtained in this medium. What is particularly required is some kind of practical list or guide, drawn up by an expert, from which libraries could make their selections. A systematic list covering the various arts of design, historical painting, sculpture, architecture, etc., would be of great service. Photographs of great public events, ceremonials, buildings, etc., and of eminent personages, would have to be purchased according to means, and, as every one knows, this might be made an endless matter. There is no reason, however, why public libraries should not preserve good photographs of the most eminent authors, artists, musicians, scientists, military commanders, royal personages, etc. Portraits of such persons are not always easy to find in books, when required, especially as the _A. L. A. Portrait-Index_ is limited in scope; therefore a separate collection of portraits in alphabetical order would be a valuable addition to a public library. In this connexion it is useful to remove portraits of celebrities, views, etc., from worn-out books and magazines, and preserve them along with all other appropriate matter. [3] The matters thus marked are dealt with more fully under the Division on Reference Work, but are included here for the sake of giving a complete conspectus of the material involved in selection.--ED. [4]=195. Lantern Slides.=--In libraries which possess lecture-rooms or other suitable accommodation, it is often desirable to collect lantern slides on such subjects as local topography and history, or on topics which illustrate bibliographical and kindred subjects. These will be found very useful, and as the collection increases, sets can be lent out to societies or individuals who require them for lectures. The cost of storing and cataloguing the slides is not great, and they are undoubtedly a valuable addition to the pictorial side of literature. [4] The matters thus marked are dealt with more fully under the Division on Reference Work, but are included here for the sake of giving a complete conspectus of the material involved in selection.--ED.