Although the Emeralite Company has the primary name recognition with these lamps, this one is not a second class citizen by any means.  The lamp is constructed of solid brass and is weighted in the base section with a cast iron counter-balance.  The only mark found on it was on the adjustment knob for the angle knuckle and it says PLA Brass Co. we think.  We re-wired it but used the original socket.  The only apology is that there is a chip on the  dark green cased shade on the front left corner (shown below with an arrow pointing to it).  The lamp was meant to be able to sit on top of an upper ledge and the weighted base would allow you to place the light directly overhead of your work area.  Perfect for Roll Top Desks or Upright Pianos.  

Size ................ 6" Diameter Base x 10" Wide Shade - Height adjusts from 6" to 19"
Circa .................. 1915-30
Price ................... $395