Playing Checkers with Electric Lights 



Do you want to draw a crowd in front of your 

 place? This bulletin-board game will do it 



Red and green lights are used for checkermen and a white light for a king. There are one 



thousand nine hundred and twenty lamps displayed upon the board and one thousand and 



twenty-four in the checker squares. About sixty thousand variations may be shown 



ANTHONY NELSON of St. Paul, 

 /-\ Minnesota, is the inventor of a board 

 which plays checkers and other 

 games automatically. When the board is 

 used for playing checkers it is capable of 

 showing sixty thousand or more variations. 

 The games or records are worked out on 

 sheet brass and then placed on a cylinder 

 which revolves slowly, requiring twenty- 

 five minutes to make one revolution. The 

 time required for each game is about eight 

 minutes. 



The operation of the board may be 

 described as follows : On the surface of the 

 brass sheets is a series of grooves to con- 

 form with the particular checker game 

 being played on the board. Riding on the 

 surface of these records, which are not 

 unlike the records of the old-time music 

 boxes, are ninety-six arms of a non- 

 conducting material. On the underside of 

 the arms is placed a runner or needle on a 



slant. These runners or needles drag on 

 the surface of the cylinder as it revolves. 



Each arm is pivoted at one end. On the 

 upper edge the conducting bar is secured 

 with the contact point at the free end. As 

 the cylinder revolves the runners engage 

 with grooves on the record, raising or 

 lowering the arms. When the arms are 

 raised the circuit is broken and the checker 

 squares controlled by those arms are 

 darkened. At the contact point is a groove 

 extending longitudinally across the terminal 

 board. Mercury is used to insure a perfect 

 electrical circuit, as any failure of the lamps 

 to light on the board would spoil the effect 

 of the game. It requires three arms to 

 control each square on the checker board. 



The color scheme is red and green lights 

 for the checkermen, and a white light for 

 the king. When the king is in play a letter 

 "K" with a light background is displayed 

 at the end of the cylinder. Anyone with 



9±fi 



