Linearity testing gauge

Claim 1

A LINEARITY TESTING GAUGE COMPRISING IN COMBINATION A PAIR OF SPACED PARALLEL FIXED SUPPORTS WITH A LINE ADAPTED TO BE STRETCHED THEREBETWEEN IN PARALLEL RELATION TO A SURFACE THE LINEARITY OF WHICH IS TO BE TESTED AND UPON WHICH THE TWO SUPPORTS ARE ADAPTED TO BE PLACED, A SLIDE ADAPTED TO REST ON THE SURFACE BETWEEN SAID SUPPORTS AND TO BE MOVED LENGTHWISE OF THE LINE FROM ONE LOCATION TO ANOTHER TO CHECK RUNOUT AT EACH LOCATION RELATIVE TO A NORMAL CONDITION, A LIGHT SOURCE CARRIED ON SAID SLIDE ARRANGED TO DIRECT A BEAM OF LIGHT PARALLEL TO SAID SURFACE IN THE PLANE OF SAID LINE TOWARD THE LINE SO THAT THE LINE CASTS A SHADOW ON AN OBJECT DISPOSED ON THE OTHER SIDE OF THE LINE, AND MEANS COMPRISING TWO SOLAR CELLS IN CLOSELY SPACED, COPLANAR RELATIONSHIP, PARALLEL TO ONE ANOTHER AND THE LINE IN A PLANE AT RIGHT ANGLES TO THE LIGHT BEAM FROM THE LIGHT SOURCE DEFINING AN OBJECT ON WHICH THE LINE CASTS A SHADOW WHERE THE DEVIATION OF THE SHADOW FROM A NORMAL LINE CAN BE MEASURED, SAID SOLAR CELLS BEING ELECTRICALLY CONNECTED WITH AN AMPLIFIER WHICH IN TURN IS ELECTRICALLY CONNECTED WITH A MICRO-AMMETER ON WHICH THE DEFLECTION OF THE NEEDLE FROM ZERO IN EITHER DIRECTION ENABLES READING THE EXTENT OF RUNOUT DIRECTLY IN SMALL FRACTIONS OF AN INCH, WHEREBY THE LOCATION, EXTENT AND DIRECTION OF RUNOUT ON SAID SURFACE MAY BE DETERMINED.