Photographic postcard of people working on the Christofferson 1914 Tractor aircraft, Lone Pine, California, circa 1914.Inscription: "Christofferson Tractor Biplane / Tuning up / Lone Pine, Cal. 1900 / Forbes."
Photographic postcard the Christofferson 1914 Tractor aircraft, Bishop, California, circa 1914. A man is seated in the cockpit.Inscription: "Forbes / Christofferson Tractor Biplane / Bishop, Cal. 1889 / Dedication of Exposition the Way."
Photographic postcard of people with the Christofferson 1914 Tractor aircraft, Lone Pine, California, circa 1914.Inscription: "Forbes / Christofferson Tractor Biplane / Lone Pine, Cal. 1892."
Photographic postcard of a man, possibly Silas Christofferson, working on the propellor of the Christofferson 1914 Tractor aircraft, Bishop, California, circa 1914.Inscription: "Forbes / Christopher Tractor Biplane / Bishop, Cal. 1878."
Photographic postcard of people with the Christofferson 1914 Tractor aircraft, California, circa 1914. The man standing in the cockpit is possibly Silas Christofferson.Inscription: "Forbes / The Return / 1897. Christopherson's [sic] flight over Mt.…
Photographic postcard of the Christofferson 1914 Tractor aircraft in low flight over a field, Bishop, California, circa 1914.Inscription: "Dedication of the Exposition Way / Christofferson Tractor Biplane / Bishop, Cal. / 1875 / Forbes."
Photographic postcard of Lawrence W. Brown and Ivor Shogran with a De Havilland aircraft (tail number 23307), circa 1915.Inscription on verso: "Larry Brown / Ivor Shogran / 1915 / On the tail of the lonesome De Havilland / Shogie + myself."
Photographic postcard of the motorboat "Oregon Kid" racing Silas Christofferson in his 1915 Model D seaplane, Lake Washington, Washington, circa 1915.Caption: "Famous 'Oregon Kid,' champion motorboat of the Pacific Coast, racing with Christofferson…