My Dear Horticulturist: You were so kind as to embody in an article for your November number, on the use of steam power in the more common affairs of life, some thoughts I communicated on the subject.

The season for planting trees is now rapidly approaching, and some facts in connection with pedestrian steam-engines, induces me to ask the favor of submitting a few thoughts on the duty of land owners to plant trees, and plant them this spring.

Though the Horticulturist has frequently urged and enjoined this duty in past volumes, it doubtless has many readers in 1857 which it has never had in former years, whose particular attention is desirable, and no old reader will fail to be benefited by having this duty urged upon him again.

The necessity for thus pressing on the notice of your readers the importance of tree planting, was forcibly demonstrated by witnessing the feats of one of these pedestrian engines in cutting up the trunks of large trees into lumber for purposes of utility and necessity. The pedestrian saw-mill is by far the most energetic and terrible devastator of the forest known at present They are taken to portions of forest or timber which would never be touched if the logs had to be conveyed to watercourse or stationary steam saw-mills.

I do not object to having trees cut down and sawed into lumber for purposes of utility in building and fencing. But how long will the existing forests in America last, if the terrible havoc now annually made on them is not in some way provided for 7 This can only be accomplished by planting. We Americans inquire of ourselves in regard to most undertakings, "Will they pay?" and "Will the pay come soon?" The answers to these questions, for the most part, determine our actions. This is especially true as applied to the masses; for here and there we find persons willing to labor and wait for the reward. This is especially true in application to horticulturists and florists.

In my former letter I spoke of the good the steam-engine was capable of accomplishing for agriculturists and horticulturists. Your article called attention to two builders of portable engines, one in Delaware, the other in Ohio. I find on inquiry at the Ohio establishment, that a very large majority of the engines constructed are used for saw-mill purposes - in other words, for the destruction of the forests. They pay better is the secret, and so they send out large numbers, annually, on their double mission of life and death; life to buildings and improve-ments, death to the forests.

These pedestrian lumber-cutters appear so insignificant in locomotion, or after locating in the forests, that, without evidence, we could scarcely give them credit for the terrific energy they possess in converting trees into useful and necessary forms of lumber. One pedestrian mill will make three io five times as much lumber as any ordinary water-power or stationary steam saw-mill. Almost an acre a day of average forest or timber is required to keep one steadily at work. Yet they are only one of the many agencies at work in destroying our forests. Each year these combined agencies seem to gather new strength for the next, and the secret is, they pay. Let your readers, kind Horticulturist, make, each for himself, a rough estimate of the surface of our primal forests, each year stripped to feed the pedestrian and local saw-mills; the thousands of steam-engines propelling railway trains and steamers on our rivers, where coal is not to be had; and all the other demands for rails, shingles, fuel, cross-ties, etc. etc, and I think we shall all be of one mind in regard to our duty to take immediate measures to compensate for this energetic destruction. But the loss of the forest brings some secondary results which must not be overlooked, for their importance holds first rank.

I allude to the influence on climate and the cereal crops of our country. It is of no use to stave off the consideration of these topics, they must be met, and we of this generation may as well commence to build up, as well as destroy our forests. It must and will have its day of "small things."It must have a starting point, and you, dear Horticulturist must lend a helping hand.

Planting trees - trees that are natives - trees that are valuable for fuel alone, as well as valuable for fruits and aesthetic purposes, will pay, and pay well. But you, kind reader, who do the planting, may not get the pay, but those who come after you certainly will realize it. Benefits, varied and valuable, almost fabulous in number and kind, will flow to those who come after you, and take your places in this busy world. Money you may get more speedily by cutting down, than planting and cultivating trees during their earlier years. But your money cannot compensate for the absence of trees on our soil. Money has its uses, but it is not omnipotent. It cannot create a forest to furnish wood for utility and beauty; the price of this is time, and toil, and waiting.

Soon the fetters which now hold our soil and watercourses in close embrace will be unclasped by the advancing sun. The tender herb, the beautiful flower, as well as the humble grass, and nobler trees, will again spring into new life. The earth will again be clothed in her magnificent vegetable garniture, gladdening the eye and rejoicing the hearts of us all; while, at the same time, this terrible work of destruction to the forest will go on with redoubled energy.

Let me beseech your readers to commence now the reconstruction of the wasting forests. The time of year in which this can be done is so brief and fleeting, a little hesitation about the resolve to do so, and the moment has gone for another year.

The necessity and utility, coupled with the real pleasure of planting and protecting trees, should lead to immediate action; the ultimate beneficent results will as surely follow as that cause and effect are linked together.

F. C. McELROY. Zanesville, O., Feb. 1857.