276 DR. LOUIS YESSOT KING ON THE PROPAGATION OF SOUND IN THE FREE 
Table 5. —Long Range Acoustic Survey, September 3, 1913. 
Father Point Meteorological Observations. 
Barometer, 30 T9. Air temperature : dry bulb, 57° F.; wet bulb, 55° F. 
Wind: steady. Velocity: 10-11 a.m., 25 miles per hour; 11-12 a.m., 26 miles per hour. Direction: from W. Clouds 
strato-cumulus moving from W. Sky 90 per cent, overcast. 
Phonometer Readings. 
j Position 
No. 
Phono¬ 
meter. 
1 
o -o 
2 
0 0 
3 
0 0 
4 
o -o 
5 
o-o 
6 
0 -7 
7 
1 0 
8 
3 -8 
9 
3 0 
10 
2 -0 
11 
2 -0 
12 
4-0 
Position 
No. 
Phono¬ 
meter. 
13 
1 55 
14 
3 5 
15 
4 -0 
16 
1 -8 
17 
1 -2 
18 
1 6 
19 
1 2 
20 
1 0 
21 
0 6 
22 
0 6 
23 
0 3 
24 
0 -4 
Position 
No. 
Phono¬ 
meter. 
25 
0 '5 
26 
0 -3 
27 
0 '4 
28 
0 '4 
29 
0'25 
30 
0 '2 
31 
0 15 
32 
0 T 
33 
0 T 
34 
o -o 
35 
— 
36 
— 
Position 
No. 
Phono¬ 
meter. 
37 
OT 
38 
0 0 
39 
0 T 
40 
0 T 
41 
0 T 
42 
0 T5 
43 
0 T5 
44 
0 -2 
45 
0 '25 
46 
0 '35 
47 
0 '3 
48 
0 35 
Position 
No. 
Phono¬ 
meter. 
49 
I 
0 -45 
50 
0 '6 
51 
0 '5 
52 
0 -55 
53 
1 0 
54 
1 2 
55 
1 25 
56 
1 -o 
57 
1 5 
58 
4 -0 
59 
4 '5 
60 
2 5 
Remarks. 
1. Time, 10.30 a.m. Air temperature, 58° F. Sky partly overcast by heavy clouds. Sea moderately rough; waves 
breaking. Slight haze noticeable. Signal first heard from navigating bridge but not on main deck 10 feet lower. 2. Signal 
just audible. 35. Signal just audible. 36. Time, 11.05 a.m. Sky clearing. Air temperature, 57°F. Ship turns at end of 
course. Signal just audible. 41. Sky clearing. Sea becomes smoother. Slight haze hanging low. 48-50. Rapid 
increase in audibility as estimated by ear. 55. Sun shining brightly and clouds clearing. Sea becomes much smoother 
60. Time, 11.30 a.m. Air temperature, 58° F. Ship makes for Father Point wharf. 
Control Observations. 
Rind of Rather Poin twharf .—Mean of three phonometer readings, 3 '7. Echo, 18 seconds; maximum 4 seconds after 
termination of second blast. 
Control station .—Phonometer reading, 7 '3. 
Mean air pressure operating diaphone, 18 '2 lbs./sq. in. above atmospheric. 
