This little machine, one of the most useful inventions of the age, gives to every farmer the use of water raised by it to a higher level, and at about the same expense for the same distance, as it formerly cost to bring water in pipes, from a height above the point to which he wished to carry it. With a small stream from a spring, at a descent of a few feet, you can now force, say one seventh of the water, to any part of the farm, and raise it ten feet for every foot you have of descent or power. If properly put up, according to the location, and well protected from frost and the sediment of water, the Ram will run a year - when it ought to be taken down, cleaned and painted, and new leathers and washers put in. In November,1850,1 planned end pat up for a gentlemen in Westchester county, en Hydraulic Rem, bringing the water from a smell brook fed by a spring, 600 feet, to the house, with a rise of fifty feet to the second story. By a dam four feet high, I obtained six feet descent from the surface of the pond, to a smell well of seven feet deep, in which the Sam is placed to guard it from frost.

* On the Hudson only the blossom buds injured - and on the hill-tops thesee hare escaped. ED.

I consider it important to place the driving pipe about a foot below the surface of the pond, so that if the pond settles down in the dry season, the Ram may be supplied with water. By doing so in this esse, the Ram continued to work during the whole of the extraordinary drouth of lest summer, the water at one time sinking in the pond to within an inch of the driving pipe. This was one and a half inches in diameter, and with a No. 5 Ram, supplies the house with sixteen hogsheads a day.

The reason, however, for my troubling you with this communication, is this. From the bottom of the well where the Ram is placed, I laid a two inch glass pipe to convey the waste water to the brook; and being short of this pipe, I continued it with a six inch brick drain, about 30 feet, to the brook. Last week the well filled with water, and the Ram stopped, and as the proprietor had not cleaned the Ram and supplied it with new leathers, after running fifteen months, it was supposed that something was the matter with the Ram; but on examining the brick part of the drain pipe, I found that although laid in mortar, it was entirely filled with the roots of trees, choking it up in this short period so as to prevent the passage of the water, and thereby filling the well above the Ram, pre-venting its action. I think it may be useful to draw the attention of your correspondents to this, as it will be better to use glass, or other drain pipes impervious to fibrous roots, especially near streams where so many exist.

Now you will perceive from this statement, that those roots must have continued to grow and fill up the drain in this last severe winter, for the ram worked the whole winter through without stopping, and it was only the beginning of this month that the drain, from being entirely closed up with roots, prevented the working of the ram.

Can you give any information on this point. If roots grow below frost in winter, it would be an additional reason for transplanting in the autumn.

Yours, T. W. Ludlow, Jn.

Yonkers, N Y., Monk 9,1852.

The roots of many trees have such an affinity for running water, or rather the elements of food which that water contains, that they will penetrate drains of ordinary masonry, and, little by little, choke them up entirely, as we have twice observed, and as our correspondent's illustration clearly proves. It is also well known to physiologists that a gradual growth is always going on in the roots whenever the ground is not actually frozen.

Undoubtedly, on this account, in all parts of the country, where the ground rarely freezes more than a few inches, it is greatly advantageous to transplant in the autumn. But, on the other hand, in extreme northern countries many trees suffer, during the succeeding Winter* if planted in the autumn, from the effect of the severe cold on the branches, much more than if planted in the spring; and, as is abundantly proved, a transplanted tree is much more susceptible to cold then one well established, with its roots deep in the soil. So much is this the case that it is the opinion of some writers that a higher temperature is maintained in the trunk and branches of a tree, by mere ordinary conducting power, during severe cold, in proportion to the depth to which the roots extend - since the lower the less liable to be frozen. Hence too, the great advantage of covering the soil over the roots of comparatively tender trees, with a mulching of saw-dust, tan-bark, or any other good non-conductor - to keep the frost out.

The hydraulic ram is of incalculable value in all places where a constant small rivulet of water can bo commanded - and we notice that in some parts of the country the farmers use it for supplying their cattle-yards instead of digging wells. So.