Mr. Elwes recommends the horse chestnut for planting in towns, remarking that "next to the plane it is one of the best trees we have for this purpose, and does not seem to suffer much from smoke." I regret that I am unable to endorse this view. It is true that in towns of moderate size, and in country villages, horse chestnuts may be planted with excellent effect. I know of few more charming sights than is presented by the group of these trees in the high street of Esher when they are in flower; but in London horse chestnuts prove a lamentable failure. Living as I used to do in the neighbourhood of Sloane Street, it was a distress to me each year to watch the stunted, round-headed chestnuts in the gardens at the lower part of that thoroughfare, and in Eaton Square, unfolding their delicate fingers only to have them parched and blackened by the ruthless drought and dirt of the Metropolis. As a timber producer, the horse chestnut cannot be assigned high rank. There is no lack of quantity, for the tree increases very rapidly in bulk, but in quality the wood is soft, weak, and very perishable. Moreover, it is almost useless as fuel, and probably the only economic purpose to which it could be applied profitably is the production of wood-pulp and celluloid. The true meaning of the prefix "horse," by which this tree is distinguished from the true or Spanish chestnut, has been the subject of much discussion. Apparently it was not applied in the sense of "coarse, large," as in the terms horse-radish, horse-mushroom, etc., for the Turkish name for it is _at kastan_, signifying horse-chestnut; and this was explained in a letter written by the Flemish Dr. Quackleben to Matthiolus in 1557 (many years before the tree was known in Britain), explaining the use of the fruit as a specific against broken wind in horses. [Illustration: ASPEN TREE (_Populus tremula_)] The Poplars "Hard by a poplar shook alway, All silver green with gnarled bark; For leagues no other tree did mark The level waste, the rounding gray." There is much confusion among the different species of poplar, but it is clear that in these verses Tennyson had in view our native abele or grey poplar (_Populus canescens_), a native of Great Britain, often mistaken for the white poplar (_P. alba_), which nearly resembles the grey, and has been planted in this country, but is probably an exotic. The poet's epithet "silver green" admirably describes the foliage of the grey poplar, for some of the shoots bear green leaves, others white ones, others again green leaves on the lower part and white on the upper.