OBSERVATION OF NOVEMBER 20, 1891. | ||||||||
| OBSERVER, S.P.L. | LOCALITY, UPPER HALL, SMITHSONIAN BUILDING. | |||||||
| No. 30. Single wings. |
No. 31. Superposed wings. | |||||||
|---|---|---|---|---|---|---|---|---|
| CPm | 1516.5 | cm. | ||||||
| CG1 | 1515 | 1517 | cm. | |||||
| CFw | 1528 | cm. | ||||||
| Length (without fender) | 120 | cm. = | 3.94 | ft. | 120 | cm. = | 3.94 | ft. |
| Width over wing tips | 120 | cm. = | 3.94 | ft. | 120 | cm. = | 3.94 | ft. |
| Weight of rubber (72 grammes in each tube) | 144 | gr. = | 0.32 | lbs. | 144 | gr. = | 0.32 | lbs. |
| Total flying weight (including tail) | 432 | gr. = | 0.95 | lbs. | 506 | gr. = | 1.11 | lbs. |
| Turns of rubber | 30 | 30 | ||||||
| Diameter of propellers | 37 | cm. = | 1.21 | ft. | 37 | cm. = | 1.21 | ft. |
| Width of propellers | 7 | cm. = | 0.23 | ft. | 7 | cm. = | 0.23 | ft. |
| Pitch of propellers | 50 | cm. = | 1.64 | ft. | 50 | cm. = | 1.64 | ft. |
| Area of wings (each 992 sq.cm.) | 1984 | sq.cm.= | 2.13 | sq.ft. | Each pair 1984 sq.cm.= 2.13 sq.ft. Total 3968 sq.cm.= 4.26 sq.ft. | |||
| Area of tail | 373 | sq.cm.= | 0.40 | sq.ft. | 373 | sq.cm.= | 0.40 | sq.ft. |
Area of wings and tail in No. 30, 2357 sq. cm. = 2.53 sq. ft. 2.53 sq. ft. ÷ .95 = 2.7. Therefore, there are 2.7 or nearly 3 square feet of sustaining area to the pound. | ||||||||