. Mécanisme animal : un traité sur la locomotion terrestre et aérienne. Animal locomotion. Vol d'insectes. Graphique 189 Méthode utilisée pour la détermination de l'évolution de l'tviiiff.-Les expériences précédentes jeter grande lumière sur les traces qui nous obtenir par le frottement de l'aile de l'insecte contre le cylindre noirci. Bien que les chiffres ainsi produits sont pour la plupart incomplets, nous sommes en mesure, au moyen de leurs éléments épars, de reconstruire la figure qui a été illustré par la méthode optique. Il est à remarquer que sans inter- tir judicieusement avec les mouvements

• Contributeur: Library Book Collection / Alamy Banque D'Images
• ID de l’image: RN4W90
• Taille du fichier: 7,2 MB (297,2 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 3294 x 759 px | 27,9 x 6,4 cm | 11 x 2,5 inches | 300dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

. Animal mechanism: a treatise on terrestrial and aerial locomotion. Animal locomotion. FLIGHT OF INSECTS. 189 Graphic method employed for the determination of the move- ments of the tviiiff.—The preceding experiments throw great light on the traces which we obtain by the friction of the insect's wing against the blackened cylinder. Although the figures thus produced are for the most part incomplete, we are able, by means of their scattered elements, to reconstruct the figure which has been shown by the optical method. It is to be remarked that without sensibly inter firing- with the movements of the wing, we can obtain (races of seven or eight millimetres when the wing- is rather long. The slight flexure to which the wing- is subjected allows it to remain in contact with the cylinder to that extent; we thus obtain a partial tracing of the movement; so that if we are careful to produce the contact of the wing with the cylinder in different parts of the course passed through by the limb, we obtain a series of partial tracings which are complementary to each other, and thus allow us to deduce from them the form of a perfect curve of the revolution of a wing. Suppose, then, that in fig. 71, the curve described by the gilded wing is divided by horizontal lines into three zones : the upper one, formed by the upper loop ; that in the middle, comprehending the two branches of the 8, crossing each other and forming a sort of X; the lower one including the lower loop. By registering the movement of the middle zone, we get. Fio. 72. - -Tracinsr of the middle reyion of the course of the wing of a bee, showing the crossing of ihe two branches of the 8. One ol the branches is prolonged rai her far, but still the tracing of the lower loop has not been produced. figures somewhat resembling each other, in which the lines, placed obliquely with respect to each other, cut ra-h other. This is the case in fig. 72, the middle region of the tracing of a bee, and in fig. 73, the middle

Recherche dans la banque de photos par tags

• bookcentury1800
• bookdecade1870
• bookyear1879
• livresubjectanimall