Paint calculating slide rule

Claim 1

A PAINT CALCULATING SLIDE-RULE CATALOGUE COMPRISING IN COMBINATION A CASING HAVING FIRST AND SECOND OPPOSITE WALLS, THE FIRST WALL HAVING A LONGITUDINAL WINDOW THEREIN EXTENDING ALONG SAID WALL, THE SECOND WALL HAVING FIRST, SECOND AND THIRD TRANSVERSE WINDOWS THEREIN COACTING WITH AND A SLIDER RECEIVABLE SLIDEABLY IN SAID CASING AND COMPRISING ACCORDION-FOLDED SHEET MATERIAL WITH INNER FOLDS BETWEEN FIRST AND SECOND OUTER SHEETS, THE INNER FOLDS BEING ADAPTED TO RECEIVE ALTERNATE PRINTED INFORMATION AND COLOR SAMPLES, AND BEING OF PROGRESSIVELY SHORTER LENGTHS, TO EXPOSE END PORTIONS OF EACH FOLD, SAID EXPOSED PORTIONS HAVING SUCCESSIVELY DIFFERENT SURFACE-COATING, MATERIAL-CHARACTERISTIC-INDICATING CAPTIONS THEREON, INCLUDING THE ACTUAL COVERAGE IN SQUARE FEET PER GALLON FOR EACH SAID SURFACE COATING, SAID SECOND OUTER SHEET HAVING TWO SETS OF CAPTIONS THEREON SPACED TO CAUSE CORRESPONDING CAPTIONS OF EACH SET TO REGISTER SIMULTANEOUSLY WITHIN THE SECOND AND THIRD TRANSVERSE WINDOWS AND CORRESPONDING END CAPTIONS TO REGISTER WITH THE FIRST WINDOW, THE FIRST WALL HAVING A FIRST SCALE THEREON ALONG A LONGITUDINAL WINDOW GRADUATED IN A FIRST SURFACE DIMENSION, AND A SECOND SCALE THEREON ALONG SAID WINDOW ON THE OPPOSITE SIDE THEREOF GRADUATED IN GALLONS OF PAINT AND THE FIRST OUTER SHEET OF THE SLIDE HAVING A SCALE THEREON REGISTERING WITH THE FIRST SCALE GRADUATED IN A SECOND SURFACE DIMENSION TRANSVERSE TO THE FIRST, AND HAVING INDEX MEANS THEREON REGISTERING WITH THE SECOND SCALE FOR INDICATING THEREON AN UNCORRECTED GALLONAGE OF PAINT REQUIRED ACCORDING TO THE SETTING OF THE SLIDER SCALE, SAID SCALES AND INDEX BEING RELATED BY AN AVERAGE, PREDETERMINED NUMBER OF SQUARE FEET PER GALLON OF PAINT UPON THE FIRST SCALE, SAID CASING HAVING A LIMIT STOP LIMITING THE SLIDER TO THE POSITION AT WHICH THE OUTERMOST CAPTION OF THE INNER FOLDS REGISTERS WITH THE FIRST TRANSVERSE WINDOW.