iiicline in case of the blades of the horizontal 

 screw. If we modify their iiicline, and 

 <H(i-e their plane to lie more nearly par- 

 h\M to t lie plane of rotation of the screw, 

 tlit-n ihev can not crowd the air so far 

 away diirirg erich revohition of the screw. 

 The velocity of the screw would then ha\ e 

 to he increased in order to move ttie air 

 away at the same rate at which it was 

 moved before we modified the incline of 

 ti e blades. And since we have this mod- 

 jlication, it will simply result in a higher 

 velocity of the -crew. In the end the screw 

 would move the air awa*? at the same fare 

 as before we nutdiHed the incline of its 

 blades. Let me say Mr. A. that experi- 

 ment O'ight jiroye a particular incline ot 

 the blades of the screw to be of the tjieatest 

 importance, even if general firui(;iples do 

 indicate the reverse. Now 1 deMre lo sn>;- 

 gest. Mr. A, a plan for an a!^-^hip whu.se 

 power i.s supplied l)y stored compressed air. 

 It contains a long horizontal cylinder 

 tilled with compressed air at a very hi>;h 

 pressure. Tlie cylinder forms the body of 

 ttie air-ship, ICniarged nozzles are to be 

 placed aloiife the sides of this cylimier, 

 one row on each side, the rows extending 

 along the fnll length of the cylinder with 

 their mouths extending <lowiiward. The 

 nozzles in each row are placed one imme- 

 diately in the rear of the other. l>urn)g 

 the flight of the ship, the nozzles in each 

 row will all move through the same path 

 and present little surface for resistance 

 against the air. Their mouths which are 

 the points of suspension for the ship, are 

 placed above the center of its gravilv to 

 prevent capsizine. The compressed air 

 will flow through small pipes into the en- 

 larged nozzles and there expand and |>ro- 

 duce a lower pressure before passing out 

 from them into the op- n air. Thii^s we 

 have by means of the enlarged nozzles 

 large volumes of air flowing from them 

 under low pressure and velocity, which 

 produces a far greater reactiijn or lifting 

 power, than had the compressed air llown 

 directly into the outer, atmosphere before 

 descending to a. lower pressure and larger 

 volume. We also have a largenuiuber of 

 enlargeti nozzles, thus seeuring great nozzle 

 area and conse<jueiit economy of power. 

 In regard to the appliances to maintain 

 the ship in nn nprif;ht position during its 

 flight, and to |)revent ii from falling io case 

 of accident, the arran><ements mentioned 

 ill the air-ship above, using air jets, are 

 equally adapted lo this ca-e. lUit you 

 will understand Mr. A, that the ship (.M>uld 

 not travel as long journeys as those carry- 

 ing an engine and feul. It would have to 

 land occassionally for a renewed supply of 

 compres.sed air. You umlerstand it is pos- 

 sible to carry only a fraction of the energy 

 in the form of compresseil air. to that which 

 may be carried iu the form of oil, coal etc. 



-5- 



A — ^^l^. 13, I want to suggest placing a 

 small engine on a ship of this kind, and 

 wi.en o 1 a lout; lourney land oocas^ionally 

 ami supply fuel lor the engine, and charge 

 the ship with a new supply of compressed 

 air wliile resting ou il)e earth. iSow Mr. 

 B, would there not he a great li»«s of 

 ener);y by the ^impressed air descending 

 to ,1 low pressure before pa.ssing out 

 from the enlarged nnzzies? 



1!— Yes, but th ' material from which 

 the energy is extract; d is not carried on 

 the ship, so it makes no ditference as 

 fai as the air-ship is concerned, 



A — Mr. a, in case the cylinder if of 

 larue <liniensions, but thin and light, it 

 would hold a large quantity of air at a low 

 pressure; but if its dimens'ons are 

 smaller it vvouhl have to be very thick 

 aoii he;ivy in proportion to its dimensions, 

 to hold the sania iiU:»niity of air, because 

 of the lii).dier jiressnre which is brought 

 aliivu'. Ndw it is desirable to have the 

 duuHiisioiis of il)e cylinder small as 

 possible in order that u may be less 

 bu.ky. But the smaller cylinder must 

 Inild an e(iual amount of air it) that of 

 the lar^'er one, ind>pendent of its pres- 

 sure. We must have the large ouantity 

 of air independent of the dimensions of 

 the cylinder, or pressure of the air within 

 it. 



A— Mr B, I want to ask you tins cjues- 

 tion : VV(nild there be any difference 

 in the weights of tlie large and small 

 cylinders, capable of holding equal ([uan- 

 titi'.s of compressed air at the ditlerent 

 pressures '.' 



15- Suppose Mr. A, we have a cylinder 

 one foot long and one foot in diameter, 

 and we have anotln-r one one foot long 

 and six inches in diameter. Each cylimh-r 

 is made of one-eighth inch steel. We 

 will compress within the larger cylinder 

 two cubic teet of air from its normal 

 pressure to or.e atmospnere. We will 

 compress within the smaller cylinder one 

 cubic foot of air The pressure in the 

 larger cylind r we suppose lo be fifteen 

 pounds per square inch, and in the 

 smaller one thirty pounds per s(piare 

 inch. The smaller cylinder has a strain 

 double that of the lartrer one, but it can 

 stand double the pressure, because it 

 contains only one-half Hie diameter of 

 the larger one. The smaller cylinder 

 conrains one-half the *|uaniity of air to 

 that of the larger one, iis weight is also 

 one-half that of the larger cylinder, and 

 wesupi-ose the two cylinders contain all 

 the pressure they can bear. Now if we 

 make the smaller cylinder of one-fonrtli 

 inch steel in place of one-eighth, as 

 before, we double its weight and strength. 

 And being thus strengthened we can 

 compress within it twice the (juantity of 

 air it contained before. It will then con- 



