Device for grading test papers

Claim 1

APPARATUS FOR GRADING A TEST PAPER WHICH HAS A MULTIPLE CHOICE OF ANSWERS TO EACH OF A PLURALITY OF TEST QUESTIONS, AND THE ANSWERS CHOSEN ARE INDICATED BY MARKING SELECTED AREAS ON THE TEST PAPER WITH ELECTRIALLYCONDUCTIVE MATERIAL, COMPRISING, FOR EACH QUESTION TO BE GRADED, (A) FIRST AND SECOND ELECTRICAL INDICATING DEVICES, (B) A PLURALITY OF OF SPACED TERMINALS ARRANGED IN PAIRS, THERE BEING ONE PAIR OF SPACED TERMINALS PROVIDED FOR EACH DIFFERENT ANSWER TO A QUESTION, AND (C) ELECTRICAL CIRCUIT MEANS FOR SELECTIVELY CONNECTING SAID PAIRS OF SPACED TERMINALS IN CIRCUIT WITH SAID INDICATING DEVICES, COMPRISING (D) A SWITCH ASSOCIATED WITH EACH PAIR OF TERMINALS AND MOVABLE TO A FIRST POSITION IN WHICH IT PARTIALLY CLOSES AN ELECTRIC CIRCUIT TO ONE OF SAID INDICATING DEVICES, AND MOVABLE TO A SECOND POSITION IN WHICH IT PARTIALLY CLOSES AN ELECTRIC CIRCUIT SHORTING OUT THE OTHER INDICATING DEVICE, (E) A SUPPORT ON THE BASE HOLDING SAID TEST PAPER SO THAT MARKED AREAS THEREOF REGISTER WITH AND BRIDGE PAIRS OF TERMINALS TO COMPLETE THE CIRCUITS PARTIALLY CLOSED BY SAID SWITCHES, (F) SAID SWITCHES BEING OPERATIVE TO CONNECT THEIR ASSOCIATED PAIRS OF TERMINALS IN SERIS CIRCUIT WITH ONE ANOTHER, WHEN DISPOSED IN SAID FIRST POSITIONS, THEREBY TO CLOSE SAID CIRCUIT TO SAID ONE INDICATING DEVICE ONLY WHEN ALL THE LAST-NAMED PAIRS OF TERMINALS ON IN CONTACT WITH ELECTRIALLY-CONDUCTIVE MATERIAL ON SAID PAPER, THEREBY TO DETECT CORRECT ANSWERS FOR A RESPECTIVE QUESTION.