. American engineer and railroad journal . a balloon with a capac-ity of 112,995 cub. ft. and a length of 229 ft. 8 in., corre-sponding to an elongation of 7 to 1, which was practicallyabout double the preceding one, and is shown in fig. 5. TheIjeam was replaced by a wooden cross-piece placed along theupper meridian, the shape of which it followed, and does notseem to me to constitute any improvement over the originaldesign. Finally, the motor and the rudder were subjected toimportant modifications. Yet Giffard did not .see that the con-siderable elongation which he had adopted required specia
. American engineer and railroad journal . a balloon with a capac-ity of 112,995 cub. ft. and a length of 229 ft. 8 in., corre-sponding to an elongation of 7 to 1, which was practicallyabout double the preceding one, and is shown in fig. 5. TheIjeam was replaced by a wooden cross-piece placed along theupper meridian, the shape of which it followed, and does notseem to me to constitute any improvement over the originaldesign. Finally, the motor and the rudder were subjected toimportant modifications. Yet Giffard did not .see that the con-siderable elongation which he had adopted required specialprecautions. Thus, with the test which was made in 1855,accompanied by Mr. Gabriel Yon, in a wind with a velocityof 13 ft. per second, the results were less fortunate than thefirst ; it lacked but very little in ending in a catastrophe. Onrising the balloon turned about on itself, escaped from thenet, and after a new fell, cut into two pieces. Theshock was produced by a sudden variation of the wind ofseveral meters^per Fir. i. From what I have said regarding the conditions which adirigable balloon must fidfil, it can be seen that the two greatdefects of the Giffard balloons were in not realizing them, eitherin permanence of form or rigidity of construction. Eitherone of these defects would have prevented success. As acces-sory defects, I will cite the following : Silk used in the inflatedportion diminished to a great extent the advantages of theelongation from the standpoint of resistance ; the consumptionof water and fuel caused a continual lightening, which wasnot compensated for by the inevitable loss of gas ; finally, theuse of illuminating gas was not a fortunate one, and the diffi-culties of the problem are so great that no one .should hesitateto inflate with hydrogen. However that nuiv be, Oiffard, wlio counted on building thefirst aerial locciniotivc, will at least have had the glory ofbuilding and showing the first balloon which could be classi-fie
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
