Both of these images were sourced from various wikipedia articles about airships and lighter than air travel. They are all public domain images. The top image is a technical drawing from an early 20th century encyclopedia. The bottom image, from the 1600s, depicts a theoretical "Vacuum Baloon." If the spheres were weightless and completely empty they would be 14% lighter than a helium balloon of the same size.
The dirigeable developped by Dupuy de Lome, in 1872. 1870s picture.
from the Brockhaus and Efron Encyclopedic Dictionary, 1890-1907
No comments:
Post a Comment
Be nice.