is not subject to any considerable error, the work being simple, the operations certain, and results known.
The reef, or bed, to be cut through, extends about four hundred yards, from N. to S., double what has been previously stated. The mistake has taken place, from the centre having only five feet at low water, and the flat bed of the rock, both above and below, from six to six and half; vessels being obliged to reduce their depth to five feet water felt no inconvenience from the previous obstacle, but the case will be totally different when the centre reef is removed to ten feet. This is now in progress, and has been gained on in an extent of about eighty yards in length, by twenty feet in breadth, and will be completed to those dimensions, through the whole extent, in one month from the time we have been fully at work.
I have adopted the plan of cutting a narrow channel, through the whole extent in the first instance, rather than working on the breadth, as I found the current swept this long narrow cut, and prevented the lodgment of any substance which might be brought in by the current, whereas the other method only produced a pool for its lodgment. It will also enable the Government to proceed to the extent they may think proper, a positive advantage having been obtained, be the channel broad or narrow. A certain breadth is necessary for the convenient passage even of small vessels, and this season I do not think it can be extended to more than fifty or sixty feet—there being at present about seventy days remaining, if it be certain that work cannot be carried on after May (a fact I do not think yet established). The Government will, I trust, permit the detachment to remain at such a distance as to allow their returning to the work in August, when the season is known to be favourable for two months. It will be a great subject of regret if the object is not now obtained, or if it should be imperfectly executed, when the success is positive and the expence inconsiderable, in comparison with the advantages to be gained. A small party can be left with a non-commissioned officer to take charge of the boats, stores, &c.—they may be the seamen.
17th. This day fired twenty-three charges, in 102-lbs. of powder, with very good effect The boats carried off 800 feet of stone. The work of the convicts under the boatswain equal to any others.
18th. This being the last day of the Buckreed festival, no work could be done. The few Roman catholic divers we got to replace the others, were not equal to the work; eight holes made by the two rafts, and 509 feet of stone removed.
20th. Fired 63-lbs. of powder, in fifteen charges; two failed from the pipes having been cut, and were the remains of what had been fired before; it being necessary to spare as much as possible the tubes, all the
