dence in an inquiry into the cause of a wreck, or for statistical purposes.

In order to make the foregoing suggestion more intelligible, let the plan be supposed to be put in practice on board of one of the London steamers, when leaving the Victoria Dock at Leith. But let it be understood that the courses which I here indicate are intended merely for illustration, and that I leave it entirely to nautical authorities to determine what would be the best courses for testing a ship's compass, whether in the case of a ship sailing from Leith, or any other port.

The ship being about ready to sail, the first duty of the pilots would be, to see that her moorings were so adjusted that her middle line would be parallel to the line of the wharf; and that being the first course printed in the pilot's Schedule of Departure, the junior pilot would write alongside of it, in the second column, the indication of the ship's compass, and so the instrument would be tested on that course before the ship left the wharf.

Assuming the compass to be all right, the ship would then be let go from her moorings, and when fairly on the middle line as she passed out at the dock-gate, the junior pilot would again enter in this column the telling of the compass; and again, when on the course from the dockgate to the mouth of the harbour. The ship would now quit the harbour, and as her head would be brought round to eastward she could, without stoppage, be laid for a few seconds of time upon a line bearing from the lighthouse on Newhaven pier to the lighthouse on Inchkeith, and the marking of the compass again entered. Then, with her head towards the mouth of the Firth, she could be laid upon a line bearing from the lighthouse on Leith pier to that on the island of May, and the indication of the compass again entered in the pilot's column, when it would be seen that while these five entries were being made, the ship, in sailing from the wharf in the Victoria Dock to the mouth of the harbour, would have made more than a quarter round of the compass to larboard, and from the dock-gate to where her head would point to the island of May, she would have made

about a quarter round to starboard. And by such an amount of precaution, no captain could take his ship to sea, in ignorance of the state of his compass, for the schedule handed to him by the pilot would show the action of the compass on each of these courses, and the amount of deflection, if any existed.

I have offered these illustrative sources as occasioning no delay, being close upon the track of the London steamers; but there can be no doubt, that a short detour to westward, first bringing the ship's head round southward, so as to close the familiar landmarks upon each other, would make the testing of the compass more complete, and the pilot's schedule a more satisfactory check to the occurrence of such wrecks as these suggestions are intended to avert.

After the foregoing precautions have been taken, however, a ship might encounter severe weather, and thereby suffer such injuries at sea as would cause deflection of the compass, and in that condition she might be overtaken by foggy weather, when the primary precautions which I have suggested having been nullified, she might still come to destruction, by running out of her course. I would therefore offer for your consideration the following suggestions for testing the state of a ship's compass at sea, with the view of averting this complicated peril :

Every sea-going ship should be furnished with two spare compasses, over and across each of which a small brass-rod had been elevated and fixed, having in its upper surface a longitudinal furrow or groove, throughout its entire length.

Then, supposing a ship so furnished to have sustained at sea an injury calculated to deflect the compass, and even though this should be a suspicion more than a certainty (for two or more compasses on deck may participate in the same injury), the ship's way should be stopped, whenever the weather is sufficiently moderate, and her compasses tested by the following means:—

Two water-buckets should be dropped over the taffrail, filled, and suspended close to the quarter stanchions, or as widely apart as possible. If the testing took place at night,

of course lanterns would be substituted for the buckets. In case of the ship having a round or ornamented stern, a stout spar, accurately squared at the ship's head, might be more convenient. The buckets should be seen clear of the water, clear of the ship, and square to her middle line.

Two boats should then be manned, each of them supplied with a compass, such as I have described. They should be pulled away from the ship in opposite directions, so as to take positions from which the two suspended buckets would be seen to close upon each other and appear as one, suspended by one rope.

The seaman in charge of the compass in each boat should now raise the instrument to his eye, and while looking along the groove in the brass-rod, order and adjust the position of the boat, until the two buckets as one would seem to hang into the groove through which he is looking. A reliable seaman should then note the marking of the compass, while another would signal to the ship the moment of observation, and thus secure instantaneous co-operation in the examination of the compasses on the ship's deck and in the boats. The boats would now be pulled back to the ship, and the observations reported to the captain.

The test could be repeated with the ship in other positions (which the circumstances would suggest), until the captain would be satisfied that he understood the state of his compass, when, in the event of his ship being overtaken by foggy weather, he would be able to perform the remaining part of his voyage with reasonable safety, and thus the perils, consequent upon running out of his course, would again be averted.

The above experiment could be performed where one boat only could be spared for the purpose, with either one or two compasses, and I think that seamen, accustomed to the experiment by being exercised in it, would not require to wait for more than tolerably moderate weather; or, to be more explicit, if the wind was sufficiently fallen to admit of boats leaving the ship without the risk of drifting, the continuance of the swelling wave would not matter much; for by seizing upon the recurring interval, when the ship and

the boat would pitch in unison, a fair observation could be made, and it should be kept in mind, that ships have been lost by running out of reckoning in foggy weather, when the sea was as smooth as a mirror, as it was in the instance of the Orion, which was lost upon the coast of Ayrshire, as I have already noticed.

Address of the President, CHARLES COWAN, Esq., on leaving the Chair, delivered at the General Meeting of the Society held on 13th November 1865.

GENTLEMEN,—Although the career of brilliant discovery, during the last few years, has not proceeded at the same rapid pace which marked the first part of this century, the energy, enterprise, and rapidity of execution in every department of industry is quite unparalleled; the public works, almost everywhere in progress, deserve our notice, not only on account of their grandeur and costliness, but because of the benefits to the human race which must follow in their train.

The concentration of three millions of souls in the capital of the empire, necessarily invests with cardinal importance the great undertakings of which it is the scene; and in drawing your attention to some of these, you will certainly find that abundant material is being laid up in store for Lord Macaulay's contemplative New Zealander, when he comes to muse on the ruined glories of London.

The Metropolitan Main Drainage Scheme was commenced in February 1859. At that time 52,000,000 gallons of sewage were daily discharged into the river. This quantity was constantly increasing, and the plan eventually adopted provided for the safe interception of 63,000,000 gallons daily, inclusive of the heavy rain-falls which generally take place in London on about twenty-four days in each year; that great project is now in rapid progress, and in about a year from this time we may expect that the entire system of drainage will be in full operation. The drainage of London is now effected by 1300 miles of sewer, and 82 miles of intercepting sewer. The works under the several contracts are very numerous, including, besides the sewers, pumping

stations, aqueducts, pen-stocks, tide-flaps, &c. The sewers cross, both above and below, navigable rivers, railways, canals, and roads; and have given rise to efforts of the highest importance and value in overcoming most formidable difficulties. It would be easy, if time permitted, to give numerous examples of the skill which has overcome these obstacles; but I will mention only one or two. The tunnel from Kennington church to the Old Kent Road runs for a distance of 1000 feet close under the basements of the houses, its top being only ten or twelve feet below the surface, and its diameter about ten feet. The water was pumped out of the sand without disturbing the latter, which would have been dangerous to the houses, at the rate of 1000 gallons per minute. Mr Bazalgette, the able engineer of the Board, had successfully devised the means of accomplishing this object. Again, the same sewer was carried through similar soil under the Grand Surrey Canal, and within eight feet of the water in it; and thirdly, the Regent's Canal, in the Caledonian Road, was tunnelled under, with only two feet distance between the top of the tunnel and the water in the canal, so that the miners could hear the barges, as they passed over their heads, scrape against the ground. The total cost of the London Main Drainage Works will be about L.4,500,000. The sum for defraying the expenditure is raised by loan, and is paid off by a 3d. rate on the metropolis, which produces L.180,262 per annum, the rateable value being L.14,421,011. The principal and interest will be paid off in forty years. Up to March last, 318,000,000 bricks, and 880,000 cubic yards of concrete (for the manufacture of which, in his portion of the works, Mr George Furness, the contractor, devised some very effective machinery), had been consumed, and 3,500,000 cubic yards of earth excavated. The total pumping power was 2380 horse-power nominal, requiring an average consumption of 20,000 tons of coals per annum, which was increased to 44,000 tons when the work was carried on night and day.

The Southern Drainage System is now in full operation, and was inaugurated by H. R. H. the Prince of Wales, who started the pumping engines at Crossness Point, in the