The Hammond typewriter was invented by James B. Hammond and first appeared on the market in the early 1880s. The Hammond was the first true competitor to the Remington Standard No. 2. The Hammond made use of a type-shuttle and hammer instead of type-bars. The C-shaped piece of hard rubber (later made of metal) had rows of characters on it, and when aligned with the paper, the spring-loaded hammer would strike from the back, leaving an even impression every time. Introduced with the Hammond was the Ideal keyboard. It was a two-row keyboard which grouped vowels and commonly used letters together. Eventually, the buyer had the option of purchasing a Hammond with an Ideal or Universal keyboard. 

Many Hammond models were manufactured up into the 1920s. In 1927, new management took over the company. When James B. Hammond died in 1913, he willed his patents to New York's Metropolitan Museum of Art. His patents were bought by the A. Frederick Hepburn Company. This company changed the name of the machine to Varityper, but they eventually went bankrupt. Frank B. Coxhead led a group of investors to purchase the company and continue producing Varitypers (in fact, some machines were even labelled as Coxhead). The Varityper became a cold typesetting device. It was electrified and updated into the 1970s, but was taken off the market in favor of photographic and electronic typesetting systems. Overall, the Hammond Typewriter Company was one of the longest lasting typewriter companies ever, existing for nearly a century.

Hammond No. 12
The Hammond No. 12 was introduced in 1905. It is very similar to the model 2, but it lacks the large metal tab the model 2 had on the front of the turret. This tab was replaced with a ribbon vibrator, so that the typist could have visible typing at all times. As well as other Hammonds, the model 12 was offered with the Ideal or Universal keyboard. An enclosed Hammond No. 12 was manufactured at one time, which looks very similar to the enclosed Multiplex. 
Hammond No. 12 #78556
My Hammond No. 12 with the Ideal keyboard has the serial number 78556.
Hammond No. 12 #113272
My Hammond No. 12 with the Universal keyboard has the serial number 113272.

Hammond Multiplex & Model 26
In 1913, the Hammond Multiplex was introduced. The name "Multiplex" came about from the fact that the machine was designed to carry two type-shuttles at a time. One knob on the top of the turret allowed the user to switch between type-shuttles, making the earlier, more expensive rack-and-pinion system superfluous. Many different versions of the Multiplex were manufactured. The open Multiplex was very similar in appearance to the model 12. It was made available with an Ideal or Universal keyboard. Hammond also manufactured an enclosed version of the Multiplex with the Universal keyboard. Some Hammond Multiplexes were sold as the Hammond Multiplex Model 26. In 1923, the Multiplex was manufactured with a folding keyboard, for maximum portability.  Both folding and non-folding versions of the enclosed Multiplex were also branded as the Model 26. At one point, the Hammond Typewriter Company also experimented with producing electrified Multiplexes.
Hammond Multiplex Model 26 #239011G2
My Hammond Multiplex also labelled as a Model 26. It does not have the folding keyboard. The serial number is 239011G2.