George Yost had been involved with Sholes & Glidden and Caligraph before launching his own machine company in 1888. It was an upstrike, blind-writing machine (meaning the typist could not see what was being typed). The typebars were arranged in a ring against a circular ink pad which resulted in perfectly aligned typeface (no ribbon to hinder the alignment). The Yost did not utilize a tab to separate upper and lower case letters, instead providing a full keyboard with keys for each.
The Yost 4 was introduced eight years after the 1 with little cosmetic difference. The main difference being the addition of better support for the frame. Models 5-8 followed with little difference from the 4 except for carriage widths.
The Yost 10 was bulkier than its predecessors, but more refined looking. The celluloid covered keys did not age well and the 10 is one of the rarest collectible writers on the market today. In 1908, the Yost 10 was replaced with the 15 which introduced a frontstrike, visible writing machine. Like most unique brands, Yost caved to the superior designs of Remington, among others. The company would stumble along through the Yost 20 before folding up shop.
Yost may have caved to market pressures and redesigned their machines beginning with the 15, but even those later frontstrike machines are things of beauty.