In 1908, aircraft and engine builder Henry L. Call founded the "Aerial Navigation Co." in Kansas, ending its activity in 1912.

"Call, 4 cilindros"

-As proof of his existence, he left two Call engines: an horizontally opposed two-cylinder, and a four-cylinder with the same arrangement.

-Interestingly one of the merits of these engines is that they advertised them as being the first to use exhaust mufflers.

-The two-cylinder engine was the E-1 model, which was liquid cooled, gave 45/50 hp, and had simple ignition.

-The four-cylinder was the EL-2, which gave 90/100 hp with a similar construction. Both engines were from 1911.

From Appendix 7: These engines were built in Kansas by Aerial Navigation Co., before WWI. They offered a horizontally-opposted two-cylinder that gave 50 hp and a 100 HP four cylinder engine. Both were of the boxer type.

From Appendix 10: We obtained a photograph of the brand's two-cylinder engine.

"Call engine details"

The company made two boxer models, the two-cylinder E1 that gave 50 hp and the four-cylinder E-2 with 100 hp.

"Call E-1, rear view"

-Although in its beginning, a few years before, they gave 45 and 90 hp respectively. But the small increase could come from the type of propeller when giving 50 and 100 hp.

"Call E-1 with a propeller of the same brand"

-In a corner of the advertisement a post-date is added in which the factory asks clients to communicate the particular usage details and ask for the "Reversible Air Propeller" prices, which may indicate the possibility of installing the engine in "pusher" or "puller" version.