MESSRS. EDITOES—1 would suggest a cheap plan for increasing the durability of railroad ties and other timbers in exposed situations. Make a cheap long tank, with a furnace under it, and place it on a railroad car. Fill it with coal tar, (which can be obtained at any of the gas works for $1 50 a barrel,) and bring it to a boiling heat. Now introduce a set of ties or timbers, and boil them for a short period, raising them up and down, by some simple contrivance, four or five times, when undergoing the operation ; then take them out, and allow them to dry for a few days. It will require but a short time to prepare timbers in this manner, and the cost is not worth naming, in comparison with the durability imparted to them over those laid down in their natural condition. One set of tar-prepared ties will last three times longer than an unprepared set. Fence-posts should also have their ends which enter the ground treated in this manner. J. SCOTTON. Newark, Ohio, January, 1858. [Our correspondent is perfectly right in his conclusions respecting the advantages to be derived from this mode of treating railroad timbers. The only objection to the process is the handling of dirty sticky timbers ; but that is of no consequence while plenty of persons can be found ready to do the work.— Ens.