1883. ] 303 (Thayer. 
To Raise and Lower Ship without using Ballast. 
Use an interior air-vessel connected with air-pump,the exterior balloon 
being connected with a strong light receiver containing hydrogen gas 
under high pressure. ‘To lower ship, pump air into interior sack and re- 
move hydrogen from exterior balloon. To ascend, remove the air from 
the interior sack and allow hydrogen to flow into balloon under pressure 
from receiver; the hydrogen in the receiver would also be utilized to sup- 
ply loss from leakage. 
To Steer Ship. 
Use rudder and also a movable nozzle, through which the force of pro- 
pulsion is applied. i 
To Hlevate or Depress Bow. 
Shift ballast or elevate or depress nozzle. 
Miscellaneous Data. 
In landing, turn the head of the acrial ship to the wind, thus avoiding 
all danger from dragging, ete. In navigating, it is only necessary to go 
high enough to clear terrestrial objects. 
Weight of motor, 40 Ibs. per H. P., loss about 15 per cent. 
Fuel, 4 lbs. per indicated H. P. per hour. 
Water, 28 Ibs. per H. P. (condense the steam), 
Giffard made envelopes successfully to contain gas with scarcely any 
loss. 
In conclusion, I would say that the general appearance of the aerial 
ship would be as follows, viz. : 
A, balloon ; B, upper deck ; O, lower deck for machinery ; D, smoke: 
stack ; E, nozzle; F, rudder ; a/, interior air-sack, 
Heample. 
d= BO } total ascending force Ad2] == 29'70 II 
1 = 110/ ¢ Total ase ig force Ad] == Q¢ 8, 
Resistance to passing through the air ata speed of twenty miles 
an hour == 29.33 lin. feet per sec., 000193 d? v? == 149.5 lbs., 
a force that can readily be obtained and applied, as I have suggested. 
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