GENTLEMEN:—It is indispensable to collect your troops not stationed, and have them divided into suitable parties, with a due proportion of police to each, and to patrol in such parts of the city as may be in the greatest danger from the rioters. This ought to be done as soon as practicable.

JOHN E. WOOL, Major-general.

After this had been issued, General Sandford reporting to me that his orders were not obeyed by General Brown, I issued the following order:

"All the troops called out for the protection of the city are placed under the command of General Sandford."

General Brown in his reply says, that he "never saw or heard of this first order." The only explanation of this, consistent with the character of both, is that General Wool sent this order to General Sandford alone—either forgetting to transmit it to General Brown, or expecting General Sandford to do it.

At all events, sent or not, it was a foolish order. One would infer from it that the whole task of putting down the riots belonged to the military, the commanders of which were to order out what co-operating force of police they deemed necessary and march up and down the disaffected districts, trampling out the lawlessness according to rule. This might be all well enough, but the question was, how were these troops, strangers to the city, to find out where "such parts of the city" were in which was "the greatest danger from the rioters?" It showed a lamentable ignorance of mobs; they don't stay in one spot and fight it out, nor keep in one mass, nor give notice beforehand where they will strike next. Such knowledge could only be obtained from police head-quarters, the focus of the telegraph system, and there the troops should have been ordered to concentrate at once, and put themselves under the direction of the Police Commissioners. Again, General Wool says he issued the following order to General Brown, on Tuesday:

"SIR:—It is reported that the rioters have already recommenced their work of destruction. To-day there must be no child's play. Some of the troops under your command should be sent immediately to attack and stop those who have commenced their infernal rascality in Yorkville and Harlem."

This order, too, General Brown says he never received. Thinking it strange, he addressed a note to General Wool's assistant adjutant-general, respecting both these orders, which had thus strangely wandered out of the way. The latter, Major Christensen, replied as follows:

"The orders of General Wool published in his report to Governor Seymour, viz.: 'That patrols of military and police should be sent through the disaffected districts;' and the one July 14th, 'To-day there must be no child's play,' etc., were not issued by me, and I cannot therefore say whether copies were sent to you or not. They were certainly not sent by me.

"C.F. CHRISTENSEN,