512 
PHILOSOPHICAL SOCIETY OF WASHINGTON. 
capacity. It was intended to make the longest trip on record. After a 
delay of 10 days, during which the currents were all from the east, the 
start was made at 4.26 p. m. A probable eddy or back current in the air 
caused a sudden drop of the balloon near the starting point, and nearly 
400 pounds of ballast were thrown over. This caused the balloon to rise 
to 15,700 feet, though it was not intended to go much above 1,500 feet. 
Results Obtained During the “World” and “Great North West” Balloon 
Voyages. 
Height. 
Temperature. 
Eel. Hum. 
Dew-point. 
-7-PO.* 
Ilann. 
Feet. 
W. 
G.N.W. 
W. 
G.N.W. 
W. 
G.N.W. 
W. 
G.N.W. 
500 
91° 
71° 
39% 
56% 
62° 
53° 
100 
98 
1,000 
89 
68 
40 
53 
61 
50 
97 
93 
87 
1,500 
87 
67 
41 
56 
60 
49 
96 
85 
2,000 
85 
65 
42 
51 
58 
47 
86 
80 
80 
2,500 
82 
60 
43 
58 
57 
46 
84 
78 
3,000 
81 
61 
45 
54 
58 
45 
87 
73 
73 
3,500 
79 
60 
47 
57 
57 
45 
85 
74 
4,000 
77 
56 
50 
66 
56 
46 
84 
73 
64 
4,500 
75 
55 
53 
69 
56 
44 
83 
72 
5,000 
73 
53 
56 
53 
56 
36 
81 
53 
56 
5,500 
72 
51 
58 * 
24 
55 
12 
80 
26 
6,000 
70 
53 
60 
13 
54 
2 
79 
13 
52 
6,500 
69 
54 
62 
11 
53 
1 
77 
12 
7,000 
67 
54 
64 
11 
52 
2 
76 
12 
48 
7,500 
65 
66 
52 
71 
8,000 
64 
65 
50 
65 
42 
8,500 
63 
63 
47 
58 
9,000 
61 
62 
45 
51 
38 
9,500 
58 
63 
45 
50 
10,000 
55 
70 
45 
49 
34 
10,500 
51 
80 
44 
48 
11,000 
48 
82 
43 
47 
31 
11,500 
47 
84 
42 
46 
12,000 
46 
86 
41 
45 
27 
12,500 
45 
84 
39 
40 
13,000 
45 
56 
32 
30 
25 
13,500 
43 
52 
27 
25 
14,000 
41 
45 
21 
19 
23 
14,500 
40 
31 
10 
14 
15,000 
40 
35 
14 
15 
21 
15,500 
37 
33 
10 
13 
*po = vapor tension at ground. 
p = vapor tension at each height. 
