Clipped and pollarded trees are an offence where the object aimed at is the realization of supposed more attractive forms; yet where the trimming is necessary, where there is a certain useful end in view, it may very properly be done without harming the trained eye.

Margining the pavements of some Dutch towns, there may be seen rows of trees, the upper, foliage-covered half of which is trimmed up in the shape of narrow vertical walls. This treatment, while not shading the house facade from the healthful rays of the sun, protects, in a measure, the occupants of each side of the street from the glare and heat coming from the opposite. Further, it presents an attractive object to the view of the upper windows, and acts as a screen between the two sets of these windows which face each other.

The same result might be produced, I suppose, by growing wistaria, the trumpet and other creepers, over a trellis of heavy iron wire, the tall posts supporting which would be of the same material, and stiffened against sudden winds by lateral rods crossing to and attached to the walls of the adjoining houses.