Instrument for computing unknown measurements of triangulations

Claim 1

AN INSTRUMENT FOR COMPUTING UNKNOWN MEASUREMENTS OF ONE SIDE OF A TRIANGLE, AND THE LIKE, COMPRISING A PROTRACTOR PLATE HAVING A 180 DEGREE SCALE THEREON AND HAVING AN ANNULAR CHANNEL FORMED PERIPHERALLY THEREOF IN ONE FACE, AN ANGLE SCALE PIVOTALLY ATTACHED AT ITS INNER END CENTRALLY OF SAID PLATE AND HAVING A VERNIER SCALE THEREON ALIGNABLE WITH SAID PROTRACTOR SCALE, THE SAID ANGLE SCALE BEING MOVABLE WITH RESPECT TO THE AXIS OF SAID PROTRACTOR SCALE, A FIRST MICROMETER ADJUSTABLY ATTACHED TO THE OUTER PERIPHERY OF SAID PROTRACTOR AND SLIDABLE ALONG SAID ANNULAR CHANNEL, THE SAID FIRST MICROMETER HAVING A SCALED STOCK AND A STEM IN SAID STOCK EXTENSIBLE AND RETRACTABLE IN RESPONSE TO THE ROTATION OF THE HANDLE OF SAID MICROMETER TO ENGAGE AND ANGLE SCALE, A SECOND MICROMETER SECURED TO SAID PROTRACTOR PLATE OPPOSITE SAID SCALE THEREON AND HAVING A SCALED STOCK AND A STEM IN SAID STOCK EXTENDIBLE AND RETRACTABLE IN RESPONSE TO ROTATION OF THE HANDLE OF SAID SECOND MICROMETER, WHEREBY THE ANGLE OF SAID ANGLE SCALE CAN BE MICROMATICALLY ADJUSTED WITH RESPECT TO THE AXIS OF SAID PROTRACTOR SCALE AND ITS ANGLE MEASURED BY SAID FIRST MICROMETER.