1905] 



KNOWLEDGE & SCIENTIFIC NEWS. 



29 



havintf a somewhat different shaped stern and contain- 

 ing- a rather larger volume of gas, namely, 2,600 

 cubic metres (94,000 c. feet). It is 58 metres long over 

 all; the greatest diameter, g m. 80, being 24 m. 90 from 

 the bow. The length is therefore about 5.6 times the 

 maximum diameter. The surface of the balloon is 

 about 1,300 square metres, and the weight of the 

 envelope is 550 kilos. The material consists of four 

 layers, one of cotton-cloth with a layer of caoutchouc, 

 one-tenth of a millimetre thick, then another of cloth, 

 and finally one of caoutchouc on the inside. 



Tlie former balloon had only two layers of cloth with 

 caoutchouc between, but it is hoped that this extra 

 layer will preserve the cotton from impurities in the 

 gas. The balloon is also varnished with seven coats of 

 a solution of caoutchouc in benzine, vulcanised with 

 sulphur, and is painted yellow outside, so as to prevent 

 the actinic light affecting the caoutchouc. So gas-tight 

 is this material that 48 hours after its inflation there 

 was no appreciable loss of gas. 



The ballonnet, which can be filled with air as 

 desired so as to keep the balloon taut, is of 500 c. 

 metres. The ventilating-fan for this purpose is driven 

 by the motor, but, when the latter is not working, may 

 be driven by a small dynamo and accumulator. 



In addition to the " manceuvring-valve " at the top 

 ot the balloon, there are some safety valves automatic- 

 ally opening under a pressure of 35 millimetres. 



The lower portion of the balloon is flat, and is rigidly 

 stretched on a horizontal oval framwork of steel- 

 tubing; below this is a long vertical " keel " of steel 

 tubing, covered with canvas, and at the after end of 

 this is pivoted the rudder. 



This horizontal plane and vertical keel impart great 

 stability to the vessel while running. 



One of the most notable features of the 1904 model 

 is a large horizontal double-rudder or fin, placed at the 

 stern of the balloon. This to modify or prevent any 

 tendency to pitch. There are also two small horizon- 

 tal rudders at the rear of the keel-frame, just in front 

 of the vertical rudder. 



The car, as before, is suspended from the oval steel 

 fiame by wire ropes, the thurst of the propellers 

 being conveyed to the main vessel by a system of rigid 

 steel tubes leading from the front of the car to the 

 front of the oval frame. 



The propelling mechanism is the same as in last 

 year's machine. A 4-cyIinder Daimler motor of 40 

 horsepower, running at speeds from 250 to 1,200 revo- 

 lutions per minute, rotates the two screw propellers, 

 one on each side of the car. These screws are 2 metres 

 44 in diameter and rotate 800 to 1,000 times a minute. 



The first voyage of the new airship took place on 

 the 4th of August. This, however, only lasted some 

 twelve minutes, being but a trial trip to test the engines 

 and steering arrangements. Everything proved highly 

 satisfactory, and a few days later a second journey was 

 undertaken. The wind on this occasion was blowing 

 13 miles an hour, yet the vessel rose and manoeuvred 

 around for a quarter of an hour at a height of 60 to 80 

 metres above the ground. 



Several other short trips were successfully made on 

 succeeding days, and on the i6th of August a longer 

 journey was undertaken. This lasted "41 minutes, 

 during which time the balloon covered a distance of 

 about 26 kilometres (16 miles). On the 28th of August 

 another ascent was made, and after 20 minutes of cir- 

 cling above the grounds, the airship descended and the 



aeronauts got out. Just then a strong gust of wind 

 caught the balloon, the tethering ropes both snapped, 

 and the balloon rose and floated away without any oc- 

 cupant ! Instead of rising, as might have been ex- 

 pected, to a considerable height and being carried off 

 to a great distance, the i)alloon seems to have kept 

 low and to have several times actually touched the 

 earth. Eventually it got caught up in a wood, 70 

 kilometres from its point of departure, and was deflated 

 and taken back to its shed, having suffered but little 

 damage. 



.\ number of other voyages were made later on, in- 

 cluding one on the 22nd of November, which lasted for 

 I hour and 33 minutes. 



On the 22nd of December, tiie last voyage of the year 

 was made, this being the thirtieth during 1904, and the 

 sixty-third trial of this tjpe of airship. All these trips 

 were conducted by M. Juchmes, the aeronaut, who was 

 usually accompanied by a mechanician and an assistant, 

 and on several occasions a passenger was also carried. 



To have accomplished all these journevs in varying 

 weather, and, with one exception, each time to have 

 safely returned to its shed, seems to prove that in this 

 airship we really have at last a machine capable of 

 navigating the air, and the promoters would appear 

 quite justified in alluding to it, as they do, as the 

 ' aerial cruiser." 



TKe Herschel Memorial 



Mr. J. P. Maclear writes from Beaconscroft. Chiddingfold, 

 Godalming : "I was doubtful about the inscription I sent you 

 for the north side of the Herschel Obelisk at Claremont, 

 Cape of Good Hope. I now send an exact copy." 



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Bronze Tablet (about 11x15 inches) of a Latin Inscription for the 

 Herschel Obelisk at Feldhausen, Cape of Good Hope. 



W. J. Herschel, Scripsit, May-July, 1904. Photo, hy A. S. Rencliil, Sell'., 1904. 



