1911 Aeronautical view of the Panama Canal, by C. P. Gray, Central Novelty Company, from the Digital Commonwealth - commonwealth 4m90fk088. (<a rel="nofollow" class="external free" href="https://www.digitalcommonwealth.org/search/commonwealth:4m90fk088">https://www.digitalcommonwealth.org/search/commonwealth:4m90fk088</a>)
C. P. Gray, Central Novelty Company
Digital Commonwealth