It was found by experience that men under these circumstances could not work more than one-fourth the time. A greater amount at once increased the sick list. Eight hours in thirty-two, or eight hours, on and twenty-four off, was found to be the best arrangement, as it made a daily change in the hours of duty for those regiments permanently detailed for work.

The organization found most advantageous in working a command permanently detailed for fatigue duty, was in divide its effective force into four equal detachments, on duty eight hours each, relieving each other at 4 a. m., 12 m., and 8 p. m. The large number of extra troops employed int he trenches each night were usually changed daily.

The engineer officers in charge of the works were divided into corresponding groups, four in each, relieving each other at 8 a. m., 4 p. m., and 12 midnight, four hours different from the time of relieving the troops. This difference enabled the engineer officer to carry the work through the period of relieving the fatigue details.

One engineer officer, having from two to four different kinds or jobs of work to superintend, was found to work advantageously in the night, with the help of non-commissioned officers of engineers, from 100 to 200 men.

The working parties of engineers and black infantry seldom carried their arms into the trenches, while the white infantry fatigue parties usually did.

NOTE Numbers 19.

COLORED TROOPS FOR WORK.

CIRCULAR.] HEADQUARTERS DEPARTMENT OF THE SOUTH,

Engineer's Office, Morris Islands, S. C., September 10, 1863.

As the important experiment which will test the fitness of the American negro for the duties of a soldier is now being tried, it is desirable that facts bearing on the question be carefully observed and recorded.

It is probable that in mo military operations of the war have negro troops done so large a proportion, and so important and hazardous, fatigue duty, as in the siege operations of this island.

As you have directed the operations of working parties of both white and black troops here, I respectfully ask, for the object above stated, an impartial and carefully prepared answer to the following inquiries, together with such other statements as you choose to make bearing on the question:

I. Courage, as indicated by their behavior under fire.

II. Skill and appreciation of their duties, referring to the quality of the work performed.

III. Industry and perseverance, with reference to the quantity of the work performed.

IV. If a certain work were to be accomplished in the least possible time, i. e., when enthusiasm an direct personal interest are necessary to attain the end, would whites or blacks answer best?

V. What is the difference, considering the above points, between colored troops recruited from the free States and those from the slave States?

Very respectfully, your obedient servant,

T. B. BROOKS,

Major, Aide-de-Camp, and Assistant Engineer.