I add my cordial approval to Lieutenant-Colonel Spaulding's suggestions. His great experience in the management of the trains gives to his remarks much weight, and I request for them an attentive consideration. The suggestions of Major Brainerd and Captain Ford have been called for and will be submitted whenever received.

W. H. PETTES,

Colonel, Commanding Fiftieth New York Volunteer Engineers.

[Inclosure Numbers 2.]

HDQRS. FIFTIETH Regiment NEW YORK VOL. ENGINEERS,
Washington, December 11, 1863.

Colonel W. H. PETTES,

Fiftieth New York Volunteer Engineers:

SIR: Your communication of the 10th instant, directing me to send to these headquarters any suggestions that I could make from my personal experience of pontoniering in compliance with the terms of the letter (a copy of which was inclosed) from Mr. Trowbridge, was received this day, and I hereby submit the following:

First. I would recommend that the rollers placed in the pontoons for the purpose of securing the lashings of the balks be removed. However they may appear theoretically, I consider that in practice they are a useless and expensive incumbrance, adding unnecessarily 78 pounds weight to the pontoons, already heavy. a

Second. That the anchors furnished be of uniform size and weight, not to exceed 100 pounds. b

Third. That all oars furnished be of uniform size and length; 16 feet is quite long enough. c

Fourth. That the balks and side-rails be made after the same pattern, notched on one side at proper distances and depth to admit the lashings. d

Fifth. That the cordage for balk and side-rail lashings be of the same size and length, that may be used for either purpose. c

Sixth. That the Birago, trestle for field purposes be abandoned altogether, involving as they do an extra amount of transportation. c They have been dragged for hundreds of miles without being used, and in very few cases, so far as my knowledge extends, where a pontoon-boat or temporary log abutment could not have been substituted with equal advantage, besides which the construction of the trestle is so imperfect that it always is necessary to prop and brace them before they are safe for the passage of artillery.

Seventh. That every train be permanently supplied with a regularly enlisted corps of drivers, enlisted and disciplined for that purpose; that the best of horses and artillery harness and saddles be used. c Trains have often been left until the last moment without transportation, and then furnished from the quartermaster's department with balky horses, or wild mules, and ignorant and cowardly and unreliable contrabands or civilians for drivers; at the same time they are expected to travel as rapidly as the best-equipped field batteries.

a These rollers were placed to expedite lashings with a limited number of men; with an ample force they are not expedient.

b One-half 90; one-half 120.

c Approved.

d Approved; with notches on two opposite sides.