A photo gallery of Yost Typewriters courtesy of Tilman Elster
The familiar YOST typewriter falls into that category commonly referred to either as 'upstrike,' or 'blind-writer,' both of which refer to those older-style machines wherein the typing actually occurs on the bottom of the platen, and thus is invisible to the operator.  It also is in that (collector) favored double-keyboard variety; when originally conceived and first built in prototype form about 1888, the office machines were upstrikes, and the debate over the merits of "full keyboard" or "shift-key" designs were still hotly debated.  Thus, although the machine appears bizarre to younger collectors, it was quite competitive when introduced.

The YOST is also, invisibly, uncommon in the sense that it has no ribbon.  Rather, it employs direct inking; the type slugs rest on inked pads, and when required to operate, must pull away from the pad and then move up and in to the platen.  When at rest, the type face portion of the type slug is facing outward from the center of the type basket, and a type guide at the print point ensures accurate alignment.  This comparative feature of inking, whether by direct means, by ink roller or by ribbon was also hotly debated when the YOST appeared, and many various machines were built and sold which used each class.  Proponents of direct inking claimed clearer and more presentable finished copy, while ribbon proponents claimed, among other things, no ink spotting on copy and cleaner maintenance as regards ink replenishment.   
YOST No. 1   s/n 7221
YOST No. 2 (New Yost 1)   s/n 8421
YOST No. 3 (New Yost 2)  s/n 11617
Note:  Short, or "brief" platen / carriage on above machine
YOST No. 4   s/n 51896
YOST No. 10    s/n 69598

The No. 10 YOST first appeared around 1902 (this example is from about 1903) and looked quite different; this was due to the incorporation of a very large number of improvements.

Not only were improvements made to various points of the key lever / type bar mechanism, but the carriage was heavily redesigned and now contained modern roller bearings.  The whole system of margin set devices was altered and improved, and the machine was more well-encased, and became heavier.  Advertising of the day began to refer to this No. 10 as "The New, Light-Running Yost." 

The improvements were considerable, but the intrinsic nature of the entire machine had caused it to become less competitive in its years of production.
By 1902, the debate over the future of visible vs. blind machines was still public and active..  Behind the scenes, though, it was already certain in just about all quarters that visible machines would take over.  Union Typewriter Company, which by this time included Yost, had been working on designs for frontsrikes for two years.  The new Union frontstrike was destined not to be offered for sale as one of the established brands, but rather would appear in 1904 as the Monarch.  The other companies continued with their upstrikes for a brief time until it was apparent that the concept was doomed.  Yost, like the others, made steps to enter the visible market by 1907 with designs for a new machine.
At right, patent filed 1907 for a new YOST design, which is very obviously a "visible." 

The Smith Premier and Yost firms both decided, in their front strike machines, to retain features that had helped them to hold their original customer bases.  In the Smith Premier, the full, or double-keyboard was retained.  In the Yost design, the direct inking design was retained.

In the illustration, the type slugs are at the center, almost directly below the platen.  The curved, arcing line (labeled 'a') shows the path of the type slug to the platen front.
YOST No. 15   s/n 021800

The design above was placed in production in 1908 as the Yost No. 15. (Or Model A.) The machine presents a completely new appearance, and dispenses with the double keyboard in lieu of a standard shift key arrangement.

According to G. C. Mares' contemporary account, early Yost No. 15 machines did not have a back-spacer, but he also mentions that later machines of this type incorporated it.  His book was written in 1909, and so we may assume that only the very earliest No. 15's were without this feature.

The Yost No. 15 was, on most points, competitive with the other visible writers of the day, and included a tabulator as standard equipment.  One attribute of the machine could have been considered as not fully modern; the Yost No. 15 was a carriage shifted machine.  The Monarch and L. C. Smith had introduced this feature at launch in 1904.
At right, patent filed 1912 and granted 1913 specifically stated to cover the conversion of the regular Yost No. 15 machine to segment, or basket, shift. 

The type-bar mechanism remains largely the same; the major equipment change is that required to move the entire type bar assembly for the purpose of shift. 

It thus goes without saying that the direct inking system was still retained even at this late date.
YOST No. 20   s/n KD65020

This is the design seen above placed into production as the No. 20 Yost.  Tilman Elster, when actually checking the No. 15 and No. 20 to confirm this difference, also noted the bar visible through the side of the No. 20 which is easily visible in this picture.  Not as easily visible is the fact that on the No. 15, there is considerable "see through" area above the type basket, through to the back of the machine, but which is blocked off by a new mounting design on the No. 20.

The No. 20 Yost appeared about 1912, and this example is thought to date from about 1916.

This machine soldiered on until 1924, when production was ended.  This was quite a late date for a machine not using a ribbon, which lends credence to those who swore by the clean, neat and professional impression left by all Yost machines and for whom no other was superior.
Yost Visible Typewriters
Commentary by Will Davis
Text by Will Davis.  All machines this page courtesy Tilman Elster.