Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer

The first successful rotary engine is generally attributed to the American F.O. Farwell in 1896; but the French Gnome engine, developed by the Seguin brothers, was much more successful in bringing the rotary to a broad aviation market beginning in 1909. The original Gnome had two valves, with the inlet in the head of the piston and exhaust in the in the cylinder head. The monosoupape, as the name signifies, had only one valve in the cylinder head, eliminating a weak feature of the earlier design, and was the most numerous model during World War I.

This was the second type of rotary aircraft engine designed by the Seguins, and the artifact was to power an aircraft designed in 1910 by Charles M. Olmsted. It drove two pusher propellers through extension drive shafts and mitre gears. Scale model wind tunnel tests indicated that the design was practical, but lack of funds prevented completion of the Olmsted aircraft.

 Display Status

This object is on display in Pre-1920 Aviation at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Pre-1920 Aviation
Object Details
Date Circa 1912 Country of Origin France Type PROPULSION-Reciprocating & Rotary Designer Laurent Seguin
Louis Seguin
 Manufacturer Societe des Moteurs Gnome et Rhône
 Physical Description Type: Rotary, 7 cylinders, monsoupape, air-cooled Power rating: 37 kw (50 hp) at 1,200 rpm Displacement: 7.98 L ( 488.5 cu in.) Bore and Stroke: 110 mm (4.33 in.) x 120 mm (4.73 in.) Weight: 78 kg (172 lb) Dimensions Other: 33 x 31 x 38 x 42 x 39 1/2in. (83.8 x 78.7 x 96.5 x 106.7 x 100.3cm)
Approximate (Weighed with Stand by Cat Forklift): 132.5kg (292lb.)
 Materials Steel, Aluminum, Preservative coating
 Inventory Number A19660001000 Credit Line Gift of the Family and Estate of Charles M. Olmsted. Ph.D. Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
For more information, visit the Smithsonians Terms of Use.