Note 42 — Chapter XII · SATURN.
Reading edition
Huygens appears to have used a refractor of 2-1/3-inch aperture and 23-feet focal length, with a power of 100, in effecting this discovery.
Reading edition
Huygens appears to have used a refractor of 2-1/3-inch aperture and 23-feet focal length, with a power of 100, in effecting this discovery.