128 THE BOULEVARDS. 



streets with some shade almost directly ; and as the trees are 

 usually trained specially for boulevard planting some little 

 effect is obtained at once ; but there can be uo doubt that it 

 is too close a system of planting, as the trees cannot grow 

 sufficiently when so much crowded. A better way would be to 

 place them five or ten feet further apart, and plant, alternately 

 with the trees destined to grace the boulevard eventually, 

 some kind that grows very rapidly when young. This would 

 help to furnish and freshen the avenue until the trees in- 

 tended to permanently adorn it have been established and 

 advanced a few years; and as soon as those of the free growing 

 nursiDg kind have become large enough to deprive their 

 neighbours of light they may be cut in vigorously, and finally 

 removed altogether. Sometimes double ranks of trees are 

 planted, but this is only wise where there are very wide 

 boulevards. It is occasionally practised in avenues — like 

 some of those that radiate from the Arc de Triomphe ; but 

 usually it has the effect of darkening the houses too much. 

 Where, as is often the case in the outer boulevards, there is 

 abundant room for a double or even treble line of trees to 

 develope without disagreeably shading the houses, they 

 should of course be planted. The trees are usually placed 

 within three and a half or four feet of the edge of the 

 footway, but there can be little doubt that it would be a 

 better plan to keep them a few feet further from the road, 

 and this would admit of giving them a larger body of soil. 

 Generally in Paris they receive too little. 



When the boulevard is marked out and levelled, if 

 the soil is of bad quality, as is nearly always the case, 

 trenches are dug in the footway, from one end of the 

 boulevard to the other. The width of this trench is 

 usually about six feet, and its depth four or five; and before 

 filling it in, drain pipes are laid along the sides, made 

 with lapped joints so that the roots shall not enter between 

 them. The trench is then filled with good garden earth, 

 raising it a little higher than the level, so as to allow for 

 settling. In this ground the trees are planted at about 

 six yards apart. They should be carefully chosen, with 

 perfect roots, and moderately pruned. Formerly the stem 



