Over the years, the machine evolved to a point where one could purchase a variety of cylinders ranging from 48 needles to 140 needles. A 48-needle cylinder would take very course yarn and would produce something similar to canvas. A 140-cylinder cylinder would take very fine yard and produce lace. That is quite a range of output from a single machine.
Realizing this, the Gearhart Knitting Machine Company settled on three basic outfits for sale, the Single, Double, and Triple Outfit. These options were related to the number of cylinders included with the machine, and quite naturally directed towards the beginning, intermediate, and advanced user. From a full-page spread published in 1925, we see the following information about this:
The Gearhart Hand Knitting Machine is offered with one, two, or three cylinders – a cylinder, so called, is that part of the machine which contains the knitting needles.
The Gearhart Single Outfit has one cylinder of 80 needles and is for those who want to make a limited kind of knitting – medium weight articles.
The Gearhart Double Outfit has two interchangeable cylinders of needles, one nearly the same as the Single Outfit cylinder, and the other having 100 needles for knitting lighter weight articles. [My Note: I believe the first cylinder would be either 60 or 72 needles, since this is a very common option on the machines in existence today].
The Gearhart Triple Outfit has three interchangable cylinders – one cylinder of 60 needles for heavy weight articles; one of 80 needles for medium weight articles; and one of 100 needles for light weight articles.
In order to be enabled to knit any type of knit goods, it would be necessary to have the Triple Outfit.
So, based on this, I would conclude that all other cylinders would be a special-order item. I have yet to see a 140-needle cylinder. But I would be very interested in hearing from anyone who has such a cylinder. Better yet, would you be interested in selling it? I would love to add this type of cylinder to the archives, alongside all the other cylinders in my collection.