The Otto was one of the earliest and most successful models of the Western Toy Company in Chicago. It was made for boys, and only in smaller sizes.
When it was introduced in 1879 it already was very oldfashioned, with wooden wheels and plain bearings. The only modern feature is in fact the front wheel brake.
It really was a toy and I write this page only because these small bicycles were the basis for the later New Otto, Rival and Crescent bicycles. Click here for my page on the Rival and New Otto.
The wonderful original 36 inch Otto you see in the picture was sold at Copake Auction in 2016. Click picture for the link. 2nd picture shows a typical 'Otto'-saddle.