In 1907, Charles Bennett began selling the Junior typewriter, which he renamed the Bennett for a second, improved model in 1910 that included a ribbon and a paper table. From the Virtual Typewriter Museum:
Two screws on the side enabled the user to lift the keyboard off the machine, in order to clean the typewheel, or change the ribbon. The keys on the miniature keyboard were fitted extremely close together. Pressing the top key in a row would bring down the ones underneath at the same time. Note the odd central place for the space key.
Introduced Sept., 1907 as "Junior" priced @ $15, by Junior Typewriter Company, 97 Worth St., New York City. Three-row keyboard, unusual in that all keys in each row go down when top key is pressed. A pantograph arrangement rotates typewheel to letter selected.
Sold as Bennett from 1910 @ $18, modified to replace ink rollers with a ribbon and spools, and added folding paper table, by Bennett Typewriter Company, Harrisburg, PA. Manufactured in Elliot-Fisher plant in Harrisburg, PA. At this time the company was controlled by Elliot-Fisher, with George F. Watt as one-time president.
Carriage easily removed by holding down space bar and sliding carriage off.
Bennet made in two finishes, black or nickel-plated. Both Bennett and Junior can be found made of cast iron or all-aluminum.
84 characters, 10" long x 5" wide x 2" high in leatherette snap-on case. Weight 4 lb.
"It is not much fun to type on," laments typewriter.be. The ortholinear layout and tiny spacebar might work, but the way it pushes the T Y and G H keys down is surely too much. It's clear from others' descriptions that it's a rather difficult typing experience.
Here's the patent for it, as posted by Greg Fudacz:
And a page from its handsome manual, from an eBay listing:
This came up in my search for a truly portable typewriter; it fell out of production before World War 1. The few I can find for sale are expensive or in rough shape. A Hermes Baby is about as small as it reasonably gets for manual models you can go right out and buy, though late 20th-century thermal electronic portables such as the Canon Typestar are much smaller and quieter, assuming the purpose of live typing on paper.