From the December 1933 edition of Modern Mechanix.
The magazine’s by-line is Yesterday’s Tomorrow Today.

“At a recent international bridge match the problem of letting people watch the play without interfering with the players was satisfactorily solved by the use of a horizontal periscope with one end suspended over the table and the other fitted through one wall of the room, so that the observers need neither be seen nor heard by the players.

From the observer’s standpoint this method of watching a bridge game is more satisfactory than standing by the table, as it permits a view of the cards held in all hands as well as a better look at those played.“