DescriptionBlack-and-white photo of the safety control board of the Holland Vehicular Tunnel, [New York City], no date, circa late 1927 or early 1928. 5-1/2" x 7-1/2" wide print, irregularly trimmed edges. Photo taken by Herbert Photos, Inc., New York City (inkstamp credit on reverse.) Negative number in image: 2472. Attached to reverse is mimeographed caption. Text of caption on reverse: Credit - Herbert Photos, Inc. XHW34514 Brains of the Tube. Photo shows: -- The remarkable automatic safety control board that is is continuously on the job, guarding the new Holland Vehicular Tunnel between New York and New Jersey. The two white bands represent tubes - one running east, the other west. Each panel is a section of the tubes, and the lights represent air and moisture. If the air becomes dangerously fouled in any section of the tubes, the air light of that section will flash, and the same will happen to the moisture light if the dampness becomes dangerous. (D-E-BH) [end]