I am exactly in the same condition as Nanz & Neuner with regard to street trees. A leaky gas pipe runs alongside of them for a considerable distance, and although I have had it thoroughly examined, and every appearance of a leak made good, the soil all removed for a considerable distance around, and the bottom of the pits made as tight with wet clay packed as close and firm as possible, yet they die off. At first there were about a dozen, but by continued trials I have got them all to take hold and grow, but four. Some have been now four years and look healthy so far. Last fall I had one large Elm that had been transplanted some years before, knowing that its roots would be in a strong condition to stand a good deal. I had all the soil permeated with the gas removed a long way around the bottom, packed over a foot thick with strong clay; but my efforts are of no avail for it is gone also. This position is in close proximity to a large main where other pipes diverge from it.

The only possible method I can think of would be to have the pipes uncovered, and a thick coating of plaster of Paris covered all around them, (or some such substance) such as I have seen on mains of heating pipes when passing through passages where their heat would be too strong. The trees mentioned in the article referred to are certainly in a bad condition, and will soon die, as the soil they are in will become more impregnated every day with the gas.

Government Grounds, Ontario, Canada.