NATURE'S OWN" SEAPLANES HUBBS 



345 



insertion of the dorsal fin partly because of position and partly because of its 

 larger area as compared with the remaining anterior part (fig. 2, F). A fish 

 may be divided into four parts by erecting a vertical at tlie origin of the dorsal' 

 intersecting its longitudinal axis (fig. 2, A). Designating these "anterior 

 dorsal ", " posterior dorsal ", " anterior ventral ", and " posterior ventral ", it 

 is at once evident that " anterior dorsal " and " anterior ventral " are practi- 

 cally identical, whereas " posterior dorsal " and " posterior ventral " are not. 



U 45 



?£ ABOVE 



rtORlZOMTAU AXIS ■ 



X •> LOWE:Ft.CAUD/vl. POKTlOn 



^s 



4 



jf 



'' SKSMIFICAMT Af%EAa 'I 

 LATERAL KEELA&E 





a'-V" 



COMFARATIVE CMARA&TCRiSUCC) 



LARaC LIFT 

 LOW SPCCO 



eooy uttlC 



STREAMLltlCO 



crpsELUR.u5 



SMALL LIFT 

 HIQH SPEED 

 DODY GRLATLY 

 3TF(.EAnLmEO 



BELLAftCA 



HALOCYPSELUS 



PECTCKAL AtlGLE 

 /•/ IflClOEMCE 



LOCt^HCCO 



D 



LOIi&lTUDlMAL 

 OlHEDRAL AMGiLC 



PELVIC AHiLE 

 inCIOEMCE 



MEOIAM AJtlS 



AXIS •/ MOTIOM' 



51-;^ r# LATERAL 

 KEtLA&t 



APPRO/; I MATE 

 TURHina AXIS 



'rORTlOIl IttvOLVtO' 

 •" HORIZOtlTAl. 

 F" STABILITY 



FiGDBE 2. — The aerodynamics of flying flshos. Reproduced by permission from paper by 

 C. M. Broder, Jr., publistied in Copeia. 



A, graphic comparison of the significant lateral Iteclage areas in eiglit species of flying 

 fislics of various sizes; B, flying fish richociieting from surface; C, Dying flsh mal<ing a 

 poor " landing " ; D, comparisons of greatest mid-sections of flying fishes and standard 

 airplane types ; E, diagram of clemonts involved in longitudinal stability as expressed in 

 a flying flsli. Angular figures Illustrative only; F, diagram of elements involved in 

 horizontal stability as expressed in a flying flsh. 



The percentage above the horizontal axis, " posterior and anterior dorsal ", as 

 compared with that below, " posterior and anterior ventral ", is about equal in 

 area, with a slight tendency for that portion below the line to be slightly 

 greater. The average of eight Cshes of various kinds shows 52.25 percent to be 

 below the axis. Comparative measurements with four modern planes' in com- 



' More properly such a vertical should pass through the center of gravity, but owing to 

 the difficulty in determining this in preserved material and the fact that the body outlines 

 are practically parallel between such a vertical and the dorsal intersection, for the 

 present purposes the latter point will suffice. 



•Based on area measurements of lateral keelage^ including b'lth sides of landing gear of 

 Pitcairn PA-7, Uppercu-Burnelli, Belanca 1930 Pacemaker and Lockheed Slrlus. 



