Columbia Millers were manufactured during the 1940s and 1950s by Columbia Enterprises, Inc., of Grays Lake, Illinois. A range of three vertical machines, the No. 1, No. 2 and No. 3, appeared to have been produced, all arranged along very similar lines. Simple in design and execution and of rather light appearance, the No. 1 miller had the upper part of its swivelling head formed into a strongly-built belt guard to which was bolted a motor platform - from where a standard, foot-mounted 1/3 hp 1750 rpm motor drove via a 4-step pulley to a hardened and ground spindle (probably fitted with either a No. 2 Morse or B & S Taper) running in Timken taper-roller bearings.  The spindle speeds of 490,  978, 1750 and 3020 rpm were rather high, but suited the compact dimensions of the machine and the type of fine, complex work it was likely to undertake. However, at odds with this was the fact that, although the head could be inclined through 90 degrees each side of vertical, there were no quill feeds either coarse or fine, all depth settings having to be made by elevating the knee -  an arrangement designed to cause the operator endless frustration as he struggled to reposition jobs that could otherwise have been done on one setting.
Direct-fitting collets were of the Brown & Sharpe No. 00 dead-length type (with a maximum capacity of 0.5" ) tightened and released not by the usual draw-bar but a spring-loaded compression mechanism controlled by a handle engaging on a shaft that protruded from between the two swivel clamp screws in the middle of the lower section of the head.
With two T-slots, the 4" x 15" table had a longitudinal travel of 9", laterally of 43/8" and vertical of 8".  Oddly, if the maker's figures are to be believed, their No. 1 miller at 365 lbs and 68 inches in height, was a more massive and taller machine than their No. 2.
If you have a Columbia milling machine or any literature about them, the writer would be interested to hear from you.

The upper part of  the vertical head was formed into a strongly-built belt guard to which was bolted a motor platform from where a standard foot-mounted 1/3 hp 1750 rpm motor drove via a 4-step pulley to a hardened and ground spindle running in Timken taper-roller bearings fitted with a No. 2 Morse Taper. 
The long boss protruding from the middle part of the head was the point where a handle fitted to operate the quick-release collet mechanism.

The knee and saddle carried relatively large diameter (0.5" x 10 Acme thread) feed screws running through bronze nuts. The handles were all of the full-circle type.

Columbia No. 3 Vertical Miller
With a full iron casting for the body, and a 7" x 26" table, this was a substantially heavier and more capable machine than the No. 2. The longitudinal travel of the table was 12", the cross feed a useful 9.5" and the vertical travel of the knee 17".
There was both a quick-action drill lever and a hand-wheel operated fine-feed fitted to the quill, which had a 41/16" movement - and the head could be inclined until it was horizontal. The head could also be moved in and out - taking the centre of the spindle to within 8" of the column - or as far as 18" away.
The motor, normally a 3-phase 1725 rpm unit (with the option of a 0.75 hp) gave four spindle speeds of 140, 318, 720 and 1725 rpm.
In 1953 the list price was $1350.

Columbia No. 2 Miller
This model was laid out on exactly similar lines to the No. 1 with a 1/3 hp 1750 rpm motor driving, via a 4-step V pulley to a hardened and ground spindle running in taper roller bearings and fitted with either a No. 2 Morse or B & S Taper. On this machine there was both a quick-action drill lever and a handwheel-operated fine-feed fitted to the quill, which had 2.5 inches of movement; combined with the swivelling head, and elevating knee, this set of features made a most versatile and useful arrangement.
Spindle speeds from a 1725 rpm motor were: 140, 318, 720 and 1725 rpm which, for a 4-speed span, is probably about as intelligent a selection as can be made to suit a standard machine.
The table, at  4" x 15", was identical to that offered on the No. 1 machine and carried the same two T slots and longitudinal, cross and vertical travels of 9",  43/8" and 8" respectively. 
Fitted to the maker's stand the miller weighed approximately 280 pounds and stood 62" high; in 1953 the list price was $725.

Unusual view underneath the knee showing the bevel gears use to elevate the assembly.

The hardened and ground spindle--probably fitted with a choice of either a No. 2 Morse or B & S taper) which ran in Timken taper-roller bearings . 
Brown & Sharpe No. 00 collets with a maximum capacity of 0.5" inches were specified - they were tightened and released by a spring-loaded mechanism controlled by a handle engaging on a shaft which protruded from between the two swivel clamping screws in the middle of the lower section of the head.