Popular Science Monthly 



247 



the slightest knowledge of checkers can 

 understand the game as it is played upon 

 the board. There are 

 one thousand nine 

 hundred and twenty 

 lamps displayed upon 

 the board and one 

 thousand and twenty- 

 four lamps in the 

 checker squares. 



The board is placed 

 in a perpendicular 

 position. It can be 

 seen at a considerable 

 distance when illumi- 

 nated at night. The 

 squares upon which 

 the checkers move 



have a circular opening or ring, behind 

 which the lamps project. When in play 

 each lamp has the appearance of a disk to 

 conform to the size of a checker in relation 

 to the checker square. 



In all checker games the opening move 

 goes to the black. The first move is con- 

 sidered an advantage, and checkers are 

 reversed after each game. On the auto- 

 matic board this rule is followed out. The 

 green checker represents the black and 

 moves first, playing from the bottom of the 

 board the first game and from the top of the 

 board the second game, reversing each 

 game. 



The board may be used for other games, 

 or for advertising purposes. 



SWITCH ARMS 



RUNNER OR 

 NEEDLE 



RECORD 



MOTOR TO TURN 

 RECORD 



SWITCH. ARMS 



As the cylinder re- 

 volves the runners 

 engage grooves on 

 the record. This 

 raises or lowers the 

 switch arms and 

 makes or breaks the 

 circuit connection 

 to the board lamps 



TERMINALS 



GROOVES 



The games or records are first worked out on 

 sheet brass and then placed on a cylinder 

 which revolves slowly. On the under side of 

 the switch arms needles, placed on a slant, 

 drag on the surface of the revolving cylinder 



Conveying Music by Wireless — A 

 Modern Miracle 



THERE is more fact than fancy in that 

 old song, "There is music in the air." 

 You can lie in your comfortable berth 

 on a liner speeding out to sea and hear 

 the clear, limpid notes of Caruso as he 

 sihgs to an opera audience on land, many 

 miles away. In the seclusion of your own 

 home you can hear the world's greatest 

 artists and catch the spirit of the audiences 

 to which they are singing, even to the 

 minutest d^ails of applause, although the 

 opera house may be in a distant city. 

 These are modern wonders wrought by 

 wireless. 



Not long ago the passengers on a steamer 

 far out on Long Island Sound had the inter- 

 esting experience of hearing musical selec- 

 tions colne in through their receivers. 

 Only recently a group of wireless engineers 

 and musicians held sensitive receivers to 

 their ears and heard music which was 

 conveyed to them by wireless from a distant 

 part of the city. 



Briefly, this demonstration was made as 

 follows: From the sound-box of a talking 

 machine the music was led into the trans- 

 mitter of a wireless sending station. Here 

 it was transformed into an electric current 

 which changed its direction several hundred 

 thousand times a second. Then it was 

 transformed into electromagnetic waves 

 which traveled in all directions away from 

 the aerial wires at the rate of 186,000 miles 

 a second — the speed of light. The waves 

 which reached the aerial wires of the re- 

 ceiving station were then absorbed and 

 converted back again into an electric cur- 

 rent. The music was then led into the 

 telephone receivers worn by the audience. 



