These suggestions, though not directly called for in the letter, are of such manifest importance that I have improved the opportunity to direct attention to them. The proportion of material as called for in the letter should be as follows, viz:

For a train of twenty-four boats:

Articles. Number. Articles. Number.

Boat-wagons (each 24 Carpenter's tools-

loaded with 7 balks.) Continued.

Chess-wagons (each 10 Hand-hammers 2

loaded with 60 chesses Broad-axes

Tool-wagon 1 Augers (From 1/2 to 3

2 inches)

Forge, containing a Chisels (from 1/2

complete set of 1 to 2 inches), set 4

blacksmith's tools for Draw-shaves

shoeing, &c.

Anchors 24 Screw-drivers 1

Cables (each 150 feet 24 Mallets 2

long)

Spring-lines 48 Brace with bits 2

Lashings (each 18 feet 480 One complete set 1

long, 8/8 cordage) calking chisels

Blocks and fall (pair) 1 Chalk-line, chalk, ---

Buckets 24 and awl and mallets ---

Wooden scoops 24 Lanterns (best 10

glass, well wired)

Boat-hooks 24 1/4 gal. can, 1 --

filler, 1/2 doz

wicking

Oars (16 feet long) 120 Common axes 50

Jack-screws 2 Shovels, long 50

handled

Instruments: Picks 25

Drawing instruments, 1 Cotton, pounds of 20

case

Field-glass 1 Grease buckets 40

Field-compasses 2 To which may be

added:

Tape-lines 2 Claw-balks 14

Carpenters' tools, as Wagon (for claw- 1

follows: balks)

Cross-cut saws 2 Extra long balks 14

Hand-saws 2 Wagon (for long 1

balks)

A liberal supply of cordage should always be taken.

The pontoon and chess wagons as now arranged and repaired by Captain Ford at this depot are the most complete and reliable.

I am, colonel, very respectfully, your obedient servant,

WESLEY BRAINERD,

Major Fiftieth Regiment New York Volunteer Engineers.

[Indorsement.]

Respectfully forwarded.

I would call attention to the remarks in regard to the trestles. I have always found them unreliable. They are bulky, costly, and of little use in the field. I would also suggest that the claw-balk is unnecessarily bulky and might be replaced with advantage by common balk cut of the same length as the claw-balk (20 feet 8 inches), with iron claws let into the wood and the ends chamfered to allow for the rise and fall of the boat without displacing or splitting the chess. a

W. H. PETTERS,

Colonel, Commanding.

[Inclosure Numbers 3.]

ENGINEER DEPOT,

Washington, D. C., December 24, 1863.

Colonel W. H. PETTES,

Commanding Fiftieth New York Volunteer Engineers:

SIR: A copy of the letter of William P. Trowbridge, esq., of New York, addressed to General Totten, was received by me some time since, and in accordance with your order accompanying it, I would

a Approved.