The Atlantic "geared-head" miller was manufactured by the Atlantic Machinery Corporation of 149 Broadway, New York. in, so far as can be ascertained, the 1930s and 1940s.
The 1 hp drive motor was held within the cast iron base - which also held the standard-fit coolant pump and tank - and drove up via twin V belts to a 6-speed gearbox, contained with the body of the miller, and holding gears which were all forged and hardened; whilst the standard machine was dispatched with a bottom speed of 150 rpm and a top of 675 rpm, alternative ranges were available to special order including 200 to 900 rpm and 3000 to 1350 rpm. The #9 Brown & Sharpe taper, forged-steel main spindle ran on ball bearings and was ground finished for its entire length.
The table had a working surface 6" x  24" and both "lever handle" and "crank" feeds to its longitudinal movement; when operated by the "crank" the travel was 18 inches, but under the control of the "lever handle" this was reduced to 12 inches; the table vertical moment was 8.5", and the cross feed 5.5". Although the cross-feed screw was fitted with a micrometer dial, the table's longitudinal movement had no feed indication at all whilst the vertical feed relied upon that old stand-by, a knee lifted by a lever and the micrometer collar against which it rested raised or lowered to alter the depth of cut.
If any reader has an Atlantic milling machine, the writer would be pleased to hear from you