ATMOSPHERE AND THE ACOUSTIC EFFICIENCY OF FOG-SIGNAL MACHINERY. 277 
Table 6.— Long Range Acoustic Survey, September 4, 1913 
Father Point Meteorological Observations. 
Barometer, 30'26. Air temperature : dry bulb, 47° F.; wet bulb, 43°F. 
Wind : steady. Velocity: 10-11 a.m., 5 miles per hour from N.W. 11-12 a.m., 3 miles per hour from the N.W. 
Weather fairly clear. Clouds moving from W. Sky 50 per cent, clouded over. 
Phonometeb Readings. 
Position 
No. 
1 
Phono¬ 
meter. 
Position 
No. 
Phono¬ 
meter. 
Position 
No. 
Phono¬ 
meter. 
Position 
No. 
Phono¬ 
meter. 
Position 
No. 
Phono¬ 
meter. 
! 
1 
0 -o 
18 
0 '7 
35 
0 '0 
52 
1 1 
69 
0'9 
2 
0 0 
19 
0 '6 
36 
0 '0 
53 
1 '7 
70 
1 '4 
3 
0 -o 
20 
0 '3 
37 
0 -o 
54 
1 '3 
71 
1 '2 
4 
0 -o 
21 
0 '3 
38 
0 -o 
55 
0'9 
72 
1 '4 
5 
0 -o 
22 
0 '2 
39 
0 '0 
56 
0 '9 
73 
1 '8 
6 
■ o-o 
23 
0 -o 
40 
0 '0 
57 
1 '2 
74 
1 0 
7 
— 
24 
0 0 
41 
0 '1 
58 
1 '2 
75 
1 Y 
8 
0 '6 
25 
0 -o 
42 
0 15 
59 
— 
76 
1 '2 
9 
2 0 
26 
0 -o 
43 
0 '3 
60 
1 '5 
77 
0'8 
10 
2 '0 
27 
o-o 
44 
1 0 
61 
1 Y 
78 
0 '3 
11 
1 '8 
28 
0 '0 
45 
1 '4 
62 
0'7 
79 
0'4 
12 
0 '6 
29 
0 -o 
46 
1 '4 
63 
1 1 
80 
0 '55 
13 
0 '8 
30 
0 -o 
47 
1 '2 
64 
1 '2 
81 
0'3 
14 
1 '2 
31 
0 -o 
48 
1 '7 
65 
0 '7 
82 
— 
15 
16 
32 
O'O 
49 
1 '7 
66 
0 '9 
83 
— 
16 
0 '6 
33 
0 -o 
50 
1 1 
67 
0 '8 
17 
1 Y 
34 
O'O 
51 
1 -o 
68 
0 '7 
Remarks. 
9.52 a.nu. Left Rimouski wharf. Sea smooth. Sun shining brightly. Air temperature, 50° F. 
1 . Start of circular course at \ mile distance from fog-signal station. 
3. No signal heard. 4-6. Signal just audible. 12-13. Time at position 12, 10.21 a.m. Ship turning at end of course. 
Phonometer in acoustic shadow of deck house. 23. Signal just audible. Father Point wharf obstructing. 24-27. Signals 
barely audible. 28-37. Time at position 28, 10.38 a.m. Course along radius to 1 mile circular course. No signals heard 
along this course. 38. Signal just audible. 39. Signal not heard. 40. Signal just audible. 58-59. Time at position 58, 
11.09 a.m. Ship turning baok along 1 mile circular course. 82. Signal not heard. 83. Time 11.38 a.m. Ship turns back 
to Father Point wharf. Air temperature, 49° F. 
Control Observations. 
End of Father Point wharf .—Mean of six phonometer readings, 4 '2. Echoes audible about 8 seconds and faint. 
Control station .—Phonometer reading, 6 '4. 
Mean air pressure operating diaphone, 17 '6 lbs./sq. in. above atmospheric. 
2 0 2 
