I hope that your May editorial notes on forestry and forest growth may be followed up. As to effect of forests on water supply, it is in question that the removal of forests increases the variability of streams that have risen in them? I suppose it is generally admitted that in American experience the average supply, taking periods of ten years, is not diminished or increased.

As to comparative rates of growth in England and America, I have had a chance to observe plantations of equal age from time to time for twenty years past in both countries, and without making exact measurements or a close analysis of conditions, my impression is that in like soils more trees, and especially European trees, grow more rapidly on this side of the Atlantic. This impression connects itself with another, which I find not to be uncommon, that the natural life of certain trees of the West of Europe, Conifers more especially, is shorter here than there. Of the Norway Spruces and Scotch Pines set out from the nursery more than twenty years ago, and which I have seen when eight or ten years old growing luxuriantly, it appears to me that of those still living, few are not now dwindling as if prematurely old. In some' cases, I have suspected them to be enfeebled by overbearing, and it would be interesting to ascertain whether these and other European trees do not produce larger crops of seed at an earlier age with us than in their indigenous climate.

There are now in our country so many well-equipped observers who had been students of trees before they came here, and they are so generally in correspondence with intelligent observers abroad, that an invitation from you might draw out some facts of value on this topic.

[It is a great pleasure to have the views of the Gardener's Monthly endorsed by so eminent and so careful an observer as Mr. Olmsted ; and it will give great pleasure to the editor and to many readers, if other intelligent correspondents will furnish the additional observations as suggested by the last paragraph of Mr. Olmsted's note.

As to the diminished quantity of water in streams and springs, as an actual result of cutting away the forests, this is a question in not merely some, but a great many quarters. It has been our province to show that the forests have nothing whatever to do with springs or streams, except in so far as they may serve in mountain sides to obstruct the flow of surface water to the low lands, and force it to sink down into the strata along which the under-ground rivers flow. Not so many years ago, when the matter was broached in the American Association, on the motion of Dr. Franklin B. Hough, the writer of this took exception to the views entertained there, and went over the meterological tables kept by the United States authorities, and published them, with other facts, in the New York Tribune. Dr. Hough noted these papers, but in his collection of items for his " Reports upon Forestry," published by the United States Government, these collated facts were not thought worthy of a place, while every point bearing on the opposite views has been carefully noted. We regret this persistency in one-sided evidence, because forestry is a question which above all others requires exact facts, whatever they may be.

In the Tribune papers the evidence that forests are a result instead of a cause of meteor-logical conditions was certainly suggestive. - Ed. G. M].