NEW YORK,

July 15, 1863.

General JOSEPH G. TOTTEN,

Chief Engineer, Washington:

SIR: Yesterday morning I had proposed to go to Sandy Hook with funds to pay June services. Not being enabled to find any means of conveyance from my quarters to the steamer at the foot of Robinson street (3 miles), I sent a messenger on foot with a small amount, and the rolls, to pay such persons as had taken their discharge. One of my clerks, previously directed to meet me at the boat, proceeded with the rolls and money, and reported to me at 9 o`clock last evening. All things were in the usual and accustomed train and condition at that post, with increased vigilance and caution on the part of Captain Putnam, commanding a company of infantry stationed there.

Since the report by the U. S. S. Ericson of an enemy`s vessel being on the eastern coast, and by order of General Wooll, all the guns at that post, and other ports in the harbor, are kept loaded. I left my quarters yesterday at 9 a. m. to proceed to my office, and found all railway communication had been stopped by a mob, and the omnibus lines were filled to excess, doing the work of the railroads, to wit: Second, Fourth, Sixth, Eighth, and Tenth? (Hudson River).

I succeeded in reaching there in a private conveyance, and found it expedient to redeposit in the sub-treasury the funds provided for paying the services at Sandy Hook (with the exception stated). I also found it expedient to send one set of my quarterly vouchers in charge if one of my clerks to his residence at Brooklyn, and the other set with another clerk to his residence on Staten Island. To this particular it is that I am led to draw your attention, that you may understand why it will not be in my power to comply with the last orders, relating to rendering accounts quarterly within a specified number of days.

The Government steam transport which has been useless for several months past, has been so far repaired as to make a trial trip. She was taken back to the wharf near the Globe Iron Works (Thirtieth street), where the mechanics yesterday morning were engaged making some alterations and modifications to their previous labors, when the mob approached, requiring every man to desist work, with other exactions. Captain Foster, who commands the steamer, by his good management got the vessel from the dock, and finally beyond reach, when the repairs continued. Since then I have not heard from her. Before leaving my office yesterday, 2p. m., all the omnibus lines had been stopped, previous to which the residence of the mayor, in Fifth avenue, near Sixteenth street, had been assaulted by the mob, and some slight damage done. Then ended all the public communication between the two ends of the city for the day. The omnibus lines have been drawn into public service, transporting troops from place to place as their services are required. This morning I have been endeavoring to find some means of going down town to my office. Neither railroad nor omnibus lines are running, and private conveyances, including hacks, are all specially engaged.

The New Haven and Harlem roads are broken up both in the city and beyond to Harlem River, in some few places enough to put a stop to all travel for the moment.

On Monday evening, when I last heard from Fort Lafayette, the employe`s of the engineer department had dismounted seven of the