Animal Locomotion Or Walking, Swimming, and Flying: With a Dissertation on Aëronautics

according action alternately angle animal arrangement artificial ascends axis backwards bat and bird bird body bones carried causing Compare consequently corresponding curves depressed descends described direction effective elastic elevated enables experiments extension extremities fact fall feathers feet figure fish flexed flexible flexion flight flying follows foot force forward given greater greatly ground hand horizontal inclined increased insect joint kite legs length less lever limbs manner motion move movements muscles muscular natural nearly necessary oblique observed opposite pinion planes portions position posterior margin present primary produced progression propelling rapid referred regarded remarkable represented resistance result reverse rise root rotating running screw secondary seen short side similar space speed spiral stroke surface swimming tail trunk twisting upwards vertical vibrate walking waved weight wing