WHAT CONSTITUTES SUPERIORITY IN AN AIR-SHIP.* 
By Commandant PAauL RENARD. 
The question has been much discussed as to what type has the 
most noteworthy qualities among the numerous devices which are 
to-day carrying men through the air. Some are partisans of the 
aeroplane, others of the dirigible, and these two camps are always in 
rivalry, sometimes in open enmity, so that unanimity is far from 
prevailing. 
In aviation there are monoplane and biplane enthusiasts, those 
who prefer aeroplanes without a tail, such as the Wrights’ machines,’ 
or with a tail, like all the others. In aerostation, or ballooning, 
some contend for the flexible type like the Ville de Paris, others for 
the semirigid type like the Republique, and lastly, others who vaunt 
the merits of the rigid type, like the Zeppelin. 
How can anyone know where to stand in the face of all these opin- 
ions? From a technical point of view, excellent arguments can be 
found in favor of each of the present types of air-ships as well as for 
those which may be later devised; specialists can discuss these ques- 
tions indefinitely. Although as far as I am concerned I have a well- 
established opinion on this point, it is not from the theoretical stand- 
point that I wish to express myself to-day, but without wishing to 
pass judgment it seems to me worth while to at least indicate the con- 
siderations on which such a judgment should be based. In a word I 
should like to determine here what, from a practical point of view, 
are the qualities which can be demanded in an air-ship, and from 
among these qualities to choose those which are of the greatest im- 
portance and which as a consequence should preferably serve as a 
criterion in passing judgment on a structure of a new kind. 
According to the point of view, very different sorts of perform- 
ances, if I may use such an expression, may be expected of an air-ship. 
You may, for example, wish to rise as high as possible in the air, and 
the capacity for upward ascension in such a case is evidently a quality 
4Translated by permission from Revue des Deux Mondes, vol. 54, Noy. 1, 
1909, pp. 181-199. 
+The Wright aeroplane is now provided with a tail, or rear horizontal 
rudder.—EKd. 
141 
