RCA Radiotron "Tube Pyramid"  Store Display
This is an RCA Radiotron "Tube Pyramid" store window or counter display from 1930.  It is meant to look like a carefully arranged pile of 18 UY-227 tubes, but the cartons were never meant to hold tubes, as can be seen below.  It is about 20 inches wide and 15 inches high.  It was found in the attic of an old RCA radio dealership, and had never been used.

Meant to be displayed along with the pyramid were individual double display cartons for the UY-224 and UY-227 tubes, as shown in the last picture.

Tube Pyramid Assembly Instructions