[3] It is interesting to notice, in this connection, the remark of Angus Smith, that a temperature of 54° F. is important in the decomposition of animal and vegetable matter.
[4] Public Parks. By John H. Rauch, M.D., Chicago, 1869.
[5] Les Arbres, quoted by Marsh.
[6] The late Dr. Francis remarked that he had noticed a marked increase in the fatality of diseases in sections of the city after the removal of trees and all vegetation.
[7] The Groundwork of Science. A Study of Epistemology. By St. George Mivart, M.D., Ph.D., F.R.S. New York: G.P. Putnam's Sons, 1898.
[8] The position of the solid rock is shown by the hammer at the extreme right, standing vertically.
[9] This photograph represents a more detailed view of the quarry wall seen in Fig. 1. The relation of the two views will be understood by observing the positions of the hammers, which are in the same place in both photographs. These photographs, as well as some of the others that follow, were taken by Mr. John L. Gardner, 2d, for the purpose of illustrating these pages.
[10] In order to obtain this sketch, a survey was made of the delta, and from the information thus gathered a model was constructed out of clay. The dimensions of the delta are about one thousand by seven hundred feet.
[11] The bottom of the cañon at this point is between four and five thousand feet below the flat surfaces in the foreground—a sheer descent of nearly a mile.
[12] To those who are interested in the subject of indentured labor in the tropics, the following statistics, compiled by me from official sources, may be of interest. The figures relate to British Guiana: