In a recent paper on Tree Planting in the Streets of Washington, Mr. W.P. Richards, surveyor of the District of Columbia, remarks that, under the plan adopted, "tree planting has never been at an experimental stage" in that city. "Washington was a city of young trees during the seventies, and in the spring of 1875 more than six thousand trees were planted, consisting of silver maples, Norway maples, American elms, American and European lindens, sugar maples, tulip trees, American white ash, scarlet maples, various poplars, and ash-leaved maples.... A careful count was made of the trees in 1887, and by comparing this with the number of trees since planted and those removed, there is found to be more than seventy-eight thousand trees, which if placed thirty feet apart would line both sides of a boulevard between Washington and New York. These consist of more than thirty varieties." Mr. Richards adds: "The planting and care of trees in Washington grows from year to year, and the future will probably demand more skill and judgment than in years past. About twenty thousand dollars is spent annually, most of it in the care of old trees. From one to three thousand young trees are planted during the spring and fall of each year. The nursery has several thousand of the best varieties ready for planting." The opinions of these authorities and the success of the work in Washington, now extending over a quarter of a century, determine beyond all question the feasibility and practicability of successfully cultivating trees in the streets of cities. And if any one doubts the power of trees cultivated in the streets to change the temperature of a city let him calculate the amount of foliage which the seventy-eight thousand trees, when full-grown, will furnish the city of Washington, taking as his basis the fact that a single tree, the Washington elm, at Cambridge, Massachusetts, when in full leafage, equals five acres of foliage, and that one acre of grass emits into the atmosphere 6.400 quarts of water in twenty-four hours, a powerfully cooling process.