AS A VEHICLE OF SOUND. 
241 
October 2 4. Partial Summary . — Observations by Mr. Douglass in ‘Palmerston’ steam-tug. Wind light, 
and sea quiet. Maximum range, syren 7f miles, feeble sounds, distinct at 5 miles. Gun unheard at 5 miles, 
low thud at 3'9, but unheard at 3 miles to windward. All sounds heard through rain and squall 3 miles 
distant. In sound-shadow, South Sand Head side, distant from station 3 miles, syren only heard. 
Afloat. Ashore. 
Wind E.S.E., 3 S.E. and E.S.E., 3 to 5 
Barometer — i 28-9 
Wet bulb — 45° to 43° 
Dry „ — 49° to 43° 
October 27. Partial Summary . — Wind strong, sea rough. At sea in axis syren heard at 6 miles ; nothing 
else. Heard also with paddles going up to 5 miles. Gun feeble at 4 miles, unheard at 5 ; horns barely 
audible at 4 miles. Wind across, force 5. Nearly dead to windward 1A mile, syren distinct through paddle- 
noises ; horns just audible ; gun seen but not heard. To leeward syren good at 5 miles, gun fair, horns feeble. 
On land to leeward all heard at 6 miles. Sounds very loud in Dover all day. 
Afloat. Ashore. 
Wind E.N.E., 6 N.N.E., 5 
Barometer — 30-00 
Wet bulb •— 44° to 41° 
Dry „ — 47° to 44° 
October 28. Partial Summary . — Thick haze round horizon, South Foreland invisible ; zenith blue ; sun 
shining. Maximum range 7| miles in axial line ; gun-report fair, syren-sound also fair ; 2400 revolutions 
rather better than 1500. At 6 miles, syren with 2400 revolutions distinctly superior to gun ; subsequently, 
vessel having drifted out of axis and the atmosphere having changed, neither gun nor syren heard at 6 miles, 
though nearly dead to leeward. Nothing heard all day on board South Sand Head light-ship ; but, through action 
of wind, sound loud in Dover, and heard in the middle of Folkestone. 
Afloat. 
N. by E. to N., 3 
30-5, falling 
48° 
51° 
Ashore. 
N.N.W. to N., 3 
30-1, falling 
45° to 39° 
49° to 40° 
Wind 
Barometer 
Wet bulb 
Dry „ 
October 29. Partial Summary. — Afloat, in axial line, high and low notes of syren faint at 7 miles ; high note 
rather better than low. Gun barely heard at 5 miles. Subsequently, gun was seen and not heard at various 
distances down to 2~ miles. Wind across, force 3. At 3|- miles dead to windward the syren was faintly heard ; 
gun not heard at 2f miles. Echoes observed to come strongest from windward. On land, to windward, 
Mr. Douglass carried sounds to between 2 and 2| miles ; to leeward Mr. Edwards heard the sounds at 7 miles ; 
and Mr. Ayres, in rear of instruments, carried the sounds inland for 5 miles. 
Afloat. Ashore. 
Wind E.S.E. to E.N.E., 3 E. to E.N.E., 4 
Barometer 30-3 29-9, falling 
Wet bulb 48° 42° to 38° 
Dry 
52’ 
48° to 44° 
October 30. Partial Summary . — No wind. Nearly at right angles to their axes, gun and syren heard at 11| 
miles : horns not heard. At 8J miles syren-sound efficient, with paddles going, strikingly superior to gun. 
Subsequently in axis, with a rising wind, no sounds heard at 6^ miles ; horns lost at a little over 5 miles ; at 
the same time gun very feeble. At South Sand Head, distance 3| miles, wind across, force 5, syren very 
feeble ; gun and horns not heard. On land, wind across, syren only heard 3 miles N.E. of South Foreland ; but 
on Folkestone Pier, 8 miles on the other side, syren heard plainly. Guns and horns not heard beyond Folke- 
stone Hill. 
2 i 
MDCCCLXXIV. 
