AS A VEHICLE OE SOUND. 
235 
“ On the afternoon of June 28th, 1862, I rode in company with General G. W. Randolph, then Secretary of 
War of the Confederate States, to Price’s house, about nine miles from Richmond ; the evening before 
General Lee had begun his attack on M c Cleleand’s army, by crossing the Chickahominy about four miles above 
Price’s, and driving in the right wing of M g CleLland’s army. The battle of Gain’s Farm was fought the after- 
noon to which I refer. The valley of the Chickahominy is about one and a half mile wide from hill top to 
hill top. Price’s is on one hill top, that nearest to Richmond ;, Gain’s Farm, just opposite, is on the other, 
reaching back in a plateau to Cold Harbour. 
“Looking across the valley I saw a good deal of the battle, Lee’s right resting, in the, valley,, the Federal 
left wing the same. My line of vision was nearly in the line of the lines of battle. I saw the advance of the 
Confederates, their repulse two or three times, and in the grey of the evening the final retreat of the Federal 
forces. 
“ I distinctly saw the musket-fire of both lines, the smoke, individual discharges, the flash of the guns. I 
saw batteries of artillery on both sides come into action and fire rapidly. Several field-batteries on each side 
were plainly in sight. Many more Were hid by the timber which bounded the range of vision. 
“ Yet looking fcr near two hours, from about 5 to 7 p.m. on a midsummer afternoon, at a battle in which at 
least 50,000 men were actually engaged, and doubtless at least 100 pieces of field-artillery, through an atmo- 
sphere optically as limpid as possible, not a single sound of the battle was audible to General Randolph and 
myself. I remarked it to him at the time as astonishing.. 
“ The cannonade of that very battle was distinctly heard at Amhurst Court-house, 100 miles west of Richmond, 
as I have been most credibly informed. 
“ Between me and the battle was the deep broad valley of the Chickahominy, partly a swamp, shaded from 
the declining sun by the hills and forest in the west (my side). 
“ Part of the valley on each side of the swamp was cleared ; some in cultivation, some not. Here were con- 
ditions capable of providing several belts of air, varying in the amount of watery vapour, arranged like laminae 
at right angles to the acoustic waves as they came from the battle-field to me. The direction of the valley is 
nearly due east and west. The part where the cannonade was heard 100- miles off was directly in the line of 
the, valley,, which, however, is a short one, less than 20 miles beyond the field. 
“ It occurred to me that, this incident might, interest you. I owe you thanks for the possible solution. 
“ Respectfully, 
“ Your obedient Servant, 
“ Professor John Tyndall.” “ R. G. H. Kean.” 
I learn from a subsequent letter that during the battle the air was still.- — J. T. 
Partial Summaries of Observations in Chronological Order. 
May 19. Partial Summary of Day's Work. — Maximum range of horns, with paddles stopped, from 3 to 4 
miles; wind almost directly across the direction of sound. On the South Sand Head side nothing heard at the 
distance of a mile ; wind opposed. On the Dover side a rapid and considerable fall of intensity; wind coin- 
cident. "Whistles markedly inferior to horns. Axes of horns perpendicular to each other. 
Afloat. Ashore. 
Wind E.N.E., 6 to 7 — 
Barometer 29‘9 — 
Wet bulb 51° — 
Dry „ 52° — 
May 20. Partial Summary of Day's Work. — Maximum range of horns, with paddles stopped, 5 to 6 miles ; 
wind force 2, the larger component in favour of sound ; sea smooth, and no noise on board. Guns heard by 
all observers at 9*7 miles ; clearly the best. At 4 miles, though the horns lingered on further, they were 
barely heard with paddles stopped. The whistles had failed previously. The atmospheric conditions, to all 
appearance, highly favourable to the transmission of the sound. 
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