but the scientist in his laboratory with his microscope may find out all these things, make accurate plans and drawings of the various parts of the insect, and leave it to skilled mechanics to spend many months in reproducing them accurately on a large scale. Such work is not an extravagance when we consider that if the doctors and the people learn to avoid yellow fever and malaria the life-insurance companies do not have to pay so much life insurance and the amount paid for one death is easily sufficient for the construction of such a model.

Pictures are very useful with exhibits. For instance, bones of extinct animals are frequently found. No one knows what these animals looked like in life, but the scientist can study the bones and compare them with the bones of animals which he is able to observe. His artist can paint these living animals and he can explain to him in what respect the bones of the extinct animal differ. By a study of the bones of the feet he may learn and explain to the artist whether the animal walked in a swamp or on rocky ground. By a study of the animal's teeth he may tell what kind of food it ate. Then the artist can make his picture very much more intelligently than otherwise would be the case, and this picture conveys to the people some idea of what the animal formerly looked like. Sometimes the artist makes a sculpture of the animal instead of a painting or to accompany the painting, so that a complete exhibit might show a skeleton with a painting, a model, a label, a map, and perhaps even another animal, such as lives to-day and is akin to the extinct animal.

Specimens are arranged together for such purposes as to illustrate the idea of evolution, to show all the different musical instruments of the world, or to show all the things found in a certain province or all the animals, plants, minerals, and so forth, of a certain region, as, for instance, a desert, and contrast them with things from a forest.

Scientific books, that have been based on specimens and illustrated by pictures of the specimens, are often placed near the exhibits of the specimens, as are also guide books, especially written for the public, that is, giving the main scientific facts translated into the language of the people, but omitting details of interest only to the scientist or as matters of record.

Some museums make a special effort to prepare timely and useful exhibits and place them most conspicuously. These are sometimes hastily made to meet an impending demand for knowledge. In 1912 the tent caterpillars were so numerous in the vicinity of Ottawa that they destroyed the leaves of many shade and ornamental trees in the city and many fruit trees

on the farms, as well as forest trees. They were even so numerous that their presence on the tracks delayed railroad trains many hours. The number of eggs on the trees in the spring of 1913 showed that this damage would be repeated, so an exhibit was prepared for the benefit of the people. One side of the case shows the life history of the tent caterpillar and some of the trees which it attacks. On the opposite side of the case are shown some of the means of controlling this pest. There are birds, photographs, lumps of chemicals, and a pail of commercial tanglefoot-an exhibit of inexpensive things that may save a city's shade trees-as useful an exhibit as one of rare objects. Magnifying glasses are used as an adjunct to this exhibit so that some of the smaller specimens may be more easily seen. When pressing need for such an exhibit is past, it may be retired or put in a less conspicuous place. This is an example of how officers of museums are endeavoring to find out what is useful to the people and to prepare helpful exhibits.

BUFFALO SPECIMENS GROUPED BY LOCAL LABOR AND CASE BUILT BY LOCAL CARPEN

TER IN ROCKY MOUNTAINS PARK MUSEUM. Such a case can be made for ten dollars wherever window sashes are available.

know, rather than of things merely curious or from so far that they do not affect us, if labeled and accompanied with models, maps and pictures, may easily be of more social service than some existing museum costing say ten times as much. In order to give this information clearly large classifying signs, smaller signs and still smaller descriptive labels are used and are as important as specimens. Besides these there are labels for each specimen chiefly to tell where that particular specimen is from and what it is. A collection of labels without any specimens might be of more service in a museum than a collection of specimens without labels. Labels asking questions may be used in a school museum to cause the visitor to observe closely and find out things for himself.

Publications are issued by various kinds of museums for as many purposes as the museums serve, such as records of research, complete catalogues giving details, popular guides calling attention briefly to the chief things of interest, and journals to interest people in museum work. Guide-books sometimes illustrate more than half the specimens exhibited, so the visitor from a thousand miles away may carry to his friends at home a glimpse of a large part of the exhibit with a full description and even with reference to authorities, for their use in case they care to pursue the subject into original sources. Some museums give such guide-books to the public, but as certain classes of people throw them away or destroy them, other museums prefer to charge a small sum for guides. This charge is usually less than the cost of the book.

Many museums now invite the people, through the public press, to avail themselves of its advantages. Often people would not know what they are missing, as of recently acquired material, and scientific news, were these not advertised in the papers. Business has found advertising to pay and museums now appreciate that it does. The citizens pay the taxes which make the scientific work of some museums possible and the staff feel in honor bound to lay aside their research for a time in order to explain in non-technical language such results of their study as may be valuable or merely interesting to the public.

Publishers are encouraged to make postcards of museum exhibits and in this way through the natural channels of trade information is spread far and wide without any expense to the

museum.

LIBRARY

Libraries constitute part of the equipment of many museums and suggest a tie between museums and other educational insti

VOL. V.-8.