COMPUTER

Description: 1. PLOT WHEEL: 30CM (D) X 0.6CM (H) SET OF WHEELS SCREWED TOGETHER AT CENTER. EACH WHEEL IS A TIN CIRCLE WITH LAMINATED PAPER COVERING IT. EACH WHEEL HAS NUMBERS AND GRAPHS FOR CALCULATING ARTILLERY CHARGES AND BEARINGS. THE TWO OUTER WHEELS HAVE CLEAR PLASTIC TABS AND FRONT INNER WHEEL HAS A TIN TAB WITH ROUNDED END. ON BOTTOM IS PLASTIC RULE WHICH PIVOTS AROUND THE MIDDLE. AT MIDDLE OF BACK IS "FT 105-H-6". FRONT WHEEL HAS VERTICAL NOTCH FOR READING NUMBERS ON THE WHEEL BELOW. ON FRONT WHEEL IS BLUE PLASTIC TAPE WITH "20 INDEP FD BTY LETHBRIDGE ALTA" RAISED ON IT. WHEEL HAS A FEW SCUFF MARKS. 2. PLOTTING RULE: 36.8CM X 7.1CM X 1.7CM WOOD RULER WITH CLEAR PLASTIC SLIDE BUILT AROUND IT. RULE IS RECTANGULAR IN SHAPE WITH MIDDLE PORTION CUT OUT TO FIT A SLIDING RULER INSIDE. BOTH THE BASE AND SLIDING RULER HAVE WHITE LAMINATED COVERINGS. BOTH SIDES OF RULER AND TOP OF BASE HAVE VARIOUS NUMBERS AND SCALES. SLIDE BUILT AROUND BASE IS TWO PIECES OF CLEAR PLASTIC RIVETED TO WOOD ENDS WHICH SLIDE ALONG LENGTH OF RULE. AT RIGHT END OF SLIDE RULE IS "HOW 105MM FT 105-H-6 PROJ, HE, M1 (METERS)". AT BOTTOM RIGHT IS OF BASE RULE IS "OCT 61 M83" AND AT LEFT CORNER IS "D SITE AND VERTICAL INTERVAL". ON BACK OF RULE BASE IS INFORMATION FOR PLOTTING AND ILLUSTRATIVE EXAMPLES FOR USE. AT BACK NEAR END IS "20 BTY" HAND PRINTED IN BLACK INK. "20 BTY" IS ALSO PRINTED ON PLASTIC SLIDE.

History: PLOTTERS WERE FOUND IN STORAGE AT THE ARMOURIES AND DONATED BY 18TH AIR DEFENSE REGIMENT. IN 2009, COMMANDING OFFICER MAJOR MIKE DUGUAY CALLED IT A MANUAL METEROLOGICAL ARTILLERY COMPUTER DEVICE OTHERWISE KNOWN AS A REED GRAPH. NARRATIVE BELOW SOLICITED FROM 18AD MAJOR MIKE DUGAY IN EARLY 2010 WHEN THIS ARTIFACT WAS EXHIBITED AS PART OF THE GALT’S TREASURES & CURIOSITIES DISPLAY. THE NARRATIVE BECAME THE BASIS FOR THE ARTIFACT’S LABEL COPY IN THE EXHIBIT. *** THIS ARTIFACT BROUGHT BACK A FLOOD OF MEMORIES AS IT WAS VERY SIMILAR TO THE SAME DEVICES I TRAINED ON BACK IN THE 1970S. I WILL ALWAYS EMOTIONALLY ATTACH THIS DEVICE TO MY BASIC OFFICER ARTILLERY TRAINING WHICH WAS EXTREMELY DEMANDING AND NOT ALWAYS PLEASANT. OF HISTORICAL INTEREST IS THAT THESE DEVICES WERE ON THE CUSP OF THE COMPUTER REVOLUTION WHICH REPLACED THEM. INTERESTINGLY, MANUAL DEVICES SUCH AS THESE, PROPERLY USED, WERE QUICKER IN THE COMPUTATION OF SIMPLE ARTILLERY FIRING DATA THAN WERE COMPUTERS. IN MANY CASES THIS IS STILL TRUE TODAY. COMPUTERS HOWEVER PROVE THEIR VALUE IN THE SPEEDY COMPUTATION OF MORE COMPLICATED AND MORE ACCURATE FIRING DATA. AS A CONSEQUENCE THESE DEVICES HAVE BEEN REPLACED ENTIRELY BY COMPUTERS IN ALL WESTERN ARMIES. THIS DEVICE WAS USED BY THE LETHBRIDGE ARTILLERY. ***