690 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 55 



Progress in aeronautics. 



Aeronautics, Vol. 1, No. 1 (July 1907), New York, pp. 23-26. S (10005 



Motor World, Vol. 3, No. 147, 1907, London, pp. 1299-1303, ill. S (100O6 



Progress (The) of aeronautics. 



Aer. World, Vol. 1, No. 9, 1903, Glenville, Ohio, p. 206. S (10007 



Progress of mechanical flight. 



Flight, Vol. 1, No. 1 (Jan. 1909), London, pp. 12-13. S (lOOOS 



Progress (The) of practical aeronautics during 1S99. (Captive balloon with 

 kerosene engine.) 



Sclent. Amer., Vol. 82, No. 8 (Feb. 24, 1900), New York, p. 117, ills. 3. S (10009 



Prohaska, Franz. Integration zweier Differential-Gleichungen, die sich auf 

 die Bewegung des Drachen beziehen. 



Zeitschr. Luftsch., IX Jahrg-., 5 Heft, 1890, Berlin, pp. 105-115. S (lOOlO 



. Theorie der Fallschirmbewegung auf Grund des Newton'schen Luft- 



widerstandsgesetzes. 



Zeitschr. Luftsch., XI Jahrg., 1 Heft, 1892, Berlin, pp. 5-14; 2 Heft, pp. 45- 

 54. S (10011 



Projekt einer wissenschaftlichen Ballonfahrt iiber die Schweizer Alpen. 



111. Aer. Mitt., Nr. 3 (Juli 1898), Strassburg, p. 87. S (10012 



Projet d'execution d'aerostats non montes capables de traverser le Sahara. 

 (Dilesteiir automatique; equilibreur automatique; materiel annexe.) 



La Rev. Teehn., T. 23, 1902, Paris, pp. 209-219. (10013 



Projets (Les) de M. Wellman pour 1907. 



L'Afirophile, 15^ annee. No. 2 (fev. 1907), Paris, pp. 41-42, ill. 1. S (10014 



Proujus, a. von. See 5074. 

 Propeller. Terms used in " Flight." 



Flight, Vol. 1, No. 8 (Feb. 20, 1909), London, p. 104. S 



Propeller molding. Some useful hints for the caster. 



Sclent. Amer. Suppl., Vol. 67, No. 1736 (April 1909), New York, pp. 228-229, figs. 

 1-12. S (10015 



Propellers. Also " Screw, Air," Helices. See 77, 93, 94, 294, 295, 461, 500, 501, 

 506, 549, 550, 1149, 1329, 1404, 1431, 1557, 1983, 2089, 2262, 2344, 2402, 

 2457, 2730, 3185, 3238, 3444, 3831, 4657, 5212, 5726, 5765, 6018, 6234, 6230, 

 6237, 6518, 6575, 6665, 7387, 7527, 8228, 8531, 8818, 9654, 9968, 10015, 11592, 

 11829, 12231, 12471, 12473, 12606, 12975. 



Propellers, Gyroscopic Action of. See 1563. 



Proposito (A) del concorso per un indicatore d'orizzontalita. 



Boll. Soc. Aer. Ital., Anno V, No. 6 (Gin. 1908), Roma, pp. 174-175, fig. 

 1, B (1001« 



