water into the powder through a small auger-hole bored for that purpose. Over 30 were removed in this way.

The third form, of which but 3 were found, consisted of 1 large 15-inch navy shell, buried like the small shell above mentioned, but having the metallic explosive apparatus like the wooden ones above described.

At least 6 torpedoes exploded accidentally, producing about twelve casualties.

NOTE Numbers 6.

OBSERVATIONS CONCERNING THE LOCATION, ORGANIZATION, AND ADMINISTRATION OF AN ENGINEER DEPOT, OR PARK, FROM EXPERIENCE IN THESE SIEGE OPERATIONS.

1. An engineer depot in the field should be located on or at the termination of the main line of communication of the army with its base of supplies, and should be provided with such storehouses or tents, shops, wharves, &c., as are necessary. If not within an extended line of fortifications, special works should be erected for its defense, in which case the depot detachment would form a part or the whole of the garrison of these works.

2. The duties belonging to an engineer depot are to obtain, by requisition, manufacture, or capture, engineer tools, machines, and materials; to preserve, repair, and issue the same, for use in engineering operations. It is related to these operations as the ordnance depot is to those of the artillery.

3. It should be under the control of the chief engineer, and subject only to his orders and those of the general commanding.

The commander of the engineer depot and his assistants should be engineer officers. For service at the depot should be a permanent detail of artificers and laborers, a portion, if not all, being engineer soldiers.

4. Stores for the engineer depot are obtained by requisition on the Chief Engineer of the U. S. Army, at Washington, D. C. These requisitions are made by the depot commander, and approved by the department chief engineer.

At the engineer depot, or under its control at other more suitable points, the manufacture and preparation of such siege material as fascines, gabions, sap-rollers, obstacle and shelter material, should be constantly in progress.

Sufficient stores should be kept constantly on hand to meet the probable exigencies of the service.

In those emergencies in which the quartermaster's department have to turn over to the engineer depot, or the reverse, tools or material, the papers accompanying the transfer should indicate plainly the use to which such stores are to be applied, in order that the accounts of these two departments may be adjusted at Washington.

The engineer depot commander should have funds and power to purchase such stores as he cannot obtain of the kind required, or with sufficient promptness, from other sources.

5. The books and files of the engineer depot should constantly show the amount of stores on hand and their condition; the localities and rates at which the different kinds of engineer material are being prepared and expended; the accessible localities at which en-