有声读物: National Geographic Magazine Vol. 02 No. 1-2

National Geographic Magazine Volume 2 Number 1 April 1890.:

• On the Telegraphic Determinations of Longitude by the Bureau of Navigation
• Report: Geography of the Land
• Report: Geography of the Air

National Geographic Magazine Volume 2 Number 2 May 1890.:

• The Rivers of Northern New Jersey, with notes on the classification of rivers in general.
• A Critical Review of Bering's First Expedition, 1725-30, together with a translation of his original Report upon it.
• Supplementary note on the alleged observation of a Lunar Eclipse by Bering in 1728-9.