Sessional_Paper_1887-1888 — Page 324

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Surface floats constructed of wood were also set adrift and watched during the day, but their course followed so closely on that of the sunker vanes that further observation of them was abandoned soon after sunset as unnecessary. A boat with adequate crew was detailed to watch the drifting of each float and to follow it day and night, and having a steam-launch at our disposal we were able to visit each float periodically and to note its change of position.

On the plan submitted herewith the relative positions of the several floats at the various times of our visits are shewn, the approximate course between each observation being sketched in. I will now briefly describe the courses of the floats.

On the morning of February the 27th (during the North East Monsoon) at 10.15 A.M. float No. 1 was set adrift off North Point on the ebb tide, the course followed by this float is indicated in the plan by a red line.

At 10.30 A.M. float No. 2 was started about three quarters of a mile east of North Point; its course is indicated by a blue line.

Both these floats got into an eddy in Quarry Bay.. No. 2 grounded in shallow water and on being moved out to the position of the surface float it closely followed the course of No. 1.

At 11 A.M. float No. 3 was set adrift off North Point and nearly made the Lyemun Pass its course being indicated by the green line.

At 12.30 p.m. No. 4 was started off North Point; its course is indicated by the brown line.

At 1 P.M. No. 5 was started about a mile and a half east of North Point; its course is indicated by the yellow line.

The tide turning shortly after 1 P.M. a strong current set in through the Lyemun Pass carrying the floats westwards.

At 2.55 P.M. float No. 6 was started off North Point on the flood tide; its course is indicated by a red line.

This float passing to the west of Green Island found its way out to sea on the afternoon of the following day.

At 5.15 P.M. float No. 7 was started off North Point, after travelling a short distance westwards this float returned on the ebb as far as the Lyemun Pass but missing the mid channel current returned on the flood. Its course is indicated by a blue line.

At 6.45 P.M. No. 8 was set adrift off North Point and after travelling westwards for four hours it returned on the ebb and passed through the Lyemun Pass at 2.30 A.M. Its course is indicated by a brown line. This completed the float experiments at North Point.

On the following day, February the 28th, a similar series of experiments was effected at Belcher's Point. At 8.45 A.M. No. 1 was started on the ebb tide and taking a westerly course, as indicated by the red line, got into shallow water to the north-west of Green Island. On being set free again this float continued its westerly course round Green Island and turning southwards made for the open sea.

At 11 A.M. float No. 2 was started and passing direct through the Sulphur Channel gained the sea; its course is indicated by a blue line.

At 1.45 P.M. No. 3 was started and also passed through the Sulphur Channel, but meeting the flood tide was carried in a north westerly direction outside of Green Island; its course is indicated by a brown line.

At 3.50, 5.10 and 6 P.M. respectively, Nos. 4, 5 and 6 were set adrift. These as indicated by the blue, red and brown lines made little progress.

At 9.25 A.M. on the 21st of August during the South West Monsoon float No. 1 started on the ebb tide, got into slack water off the west point of Quarry Bay, and remained almost stationary until the turn of the tide when it proceeded westwards arriving off the south of Stonecutters' Island at 10 P.M. During the following ebb it returned as far as Kowloon Point, and during the next flood it was carried back to the south of Stonecutters' Island arriving to the south of its previous position at 8 r.M. shewing a tendency to leave the harbour westwards; its course is indi- cated by a red line.