index 

SLIDE RULE CATALOGUE “ L I T E

Sub-List :  “BLUNDELL”

NAME MATCH
NR.
DESCRIPTION
Blundell MK. 2 Artillery 10" Mils 2914 Military slide rule of PVC, 330x47x4 mm
Front Scales: ST S A = B C = D T
Blundell & Harling 0490.45 Cocktail MixerF 3545 Food and drink slide chart of plastic, 146x83x2.5 mm
Blundell 0490.75 Concrete Volume computer 5374 Concrete slide chart of plastic, 200x46x2 mm (1970)
Front Scales: See Picture, Back Scales: See Picture
Blundell 100 3828 Generic slide rule of plastic, 139.5x27.5x4 mm
Front Scales: A = B C = D
Blundell 1066 Speed Time Distance 0546 Nautical slide chart of PVC, 176x47x2 mm
Front Scales: 1) = 2) 3) = 4), Back Scales: = 5) =
Blundell 1084 Dead Reckoning Portland 0545 Nautical disc of PVC, 133x154x4 mm (1976)
Front Scales: 1) = 2), Back Scales: 3) = 4)
Blundell 300 Academy 2922 Generic slide rule of co-polymer
Blundell 302 Log - log Academy 0531 Generic slide rule of PVC, 287x46x4 mm
Front Scales: L LL2 LL3 A = B CI C = D S T ST
Blundell 303 Rietz Academy 0532 Generic slide rule of PVC, 287x46.5x4 mm (1958-1970)
Front Scales: L K A = B CI C = D S ST T
Blundell 304 Darmstadt Academy 2923 Generic slide rule of PVC
Blundell 305 C Electro Academy 0533 Generic slide rule of PVC, 287x465x35 mm (1958-1970)
Front Scales: 1) EFF GEN.MOT. A = B CI C = D K LL2 LL3, Back Scales: = S L T =
Blundell 308 Accountants Academy 2925 Financial slide rule of PVC
Blundell 310 Academy 2905 Generic disc of PVC, 762 mm (1958-1970)
Front Scales: D = C CI A K
Blundell 310 Descal 2927 Generic disc of PVC, 762 mm (1958-1970)
Front Scales: L D = C CI A K
Blundell 312 Simplified Rietz Academy 2926 Generic slide rule of PVC
Blundell 315 Descal 3153 Generic disc of PVC, 196x10 mm
Front Scales: LL3 LL2 LL1 D = C CI A K
Blundell 316 Descal 0534 Generic disc of PVC, 196x10 mm
Front Scales: C = D
Blundell 401 Rietz Omega 2939 Generic slide rule of PVC, 297x42x9 mm (1958-1970)
Front Scales: 11inch / K A = B CI C = D L
Back Scales: = S ST T =
Blundell 402 Log - log Omega 2940 Generic slide rule of PVC
Blundell 403 Darmstadt Omega 2942 Generic slide rule of PVC
Blundell 404 Electro Omega 2928 Generic slide rule of PVC
Blundell 405 Omega 2758 Generic slide rule of PVC, 300x42x8 mm (1958-1970)
Front Scales: 11inch / A = B C = D
Blundell 407 Technico Omega 2934 Generic slide rule of PVC
Blundell 409 Mercantile Omega 2933 Financial slide rule of PVC
Blundell 601 Rietz Omega 0536 Generic slide rule of PVC, 159x33x6 mm (1958-1970)
Front Scales: 6inch / K A = B CI C = D L
Back Scales: = S S&T T =
Blundell 605 Omega 2930 Generic slide rule of plastic, 160x33x4 mm
Front Scales: 6inch / A = B C = D
Blundell 606 Omega 3915 Generic slide rule of plastic, 159x33x5 mm
Front Scales: 6in / A = B CI C = D
Back Scales: = S S&T T =
Blundell 800 2759 Generic slide rule of PVC, 306x36x4 mm (1970-1982)
Front Scales: A = B C = D
Blundell 802 Log - log Academy 0537 Generic slide rule of PVC, 330x46.5x4 mm
Front Scales: K LL2 LL3 A = B L CI C = D S T ST
Blundell 803 P (Projection) 0539 Generic projection of perspex, 363x60x5 mm
Front Scales: L K A = B CI C = D S ST T
Blundell 803 Rietz Academy 0538 Generic slide rule of PVC, 331x47x45 mm
Front Scales: L K A = B CI C = D S T ST
Blundell 808 Accountants Academy 2909 Generic slide rule of PVC, 329x46x4 mm (1970-1982)
Front Scales: S LL1 DF = CF IL IR C = D LL3 LL2
Back Scales: M = T =
Blundell 812 Classmate Academy 0540 Generic slide rule of PVC, 172x37x4.5 mm (1970-1982)
Front Scales: S T A = B CI C = D K L
Blundell 813 Classmate Academy 0541 Generic slide rule of PVC, 307x37x4.5 mm (1970-1982)
Front Scales: S T A = B CI C = D K L
Blundell 904 Academy 0542 Generic slide rule of PVC, 319x37x4.3 mm (1975-82)
Front Scales: ST A = B CI C = D S T
Back Scales: K L DF = CF CIF C = D LL2 LL3
Blundell 905 Academy 0543 Generic slide rule of PVC, 329x46.5x4 mm (1975-1982)
Front Scales: LL01 LL02 LL03 A = B L CI C = D LL3 LL2 LL1, Back Scales: K P ST DF = CF CIF CI C = D T S
Blundell AG 1 2970 Generic slide rule of co-polymer
Blundell AG 2 0511 Generic slide rule of co-polymer, 286x37x7 mm
Front Scales: 10inch / K A = B R C = D M
Back Scales: 26cm
Blundell AG 5 RIETZ 2971 Generic slide rule of co-polymer, 286x37x8 mm (1949-1958)
Front Scales: 10inch / K A = B R C = D M
Back Scales: 26cm = S ST T =
Blundell AL 6 0513 Generic slide rule of co-polymer, 284x37x8 mm (1949-1958)
Front Scales: 25cm / U.L. A = B R C = D L.L.
Back Scales: = S ST T = 10inch
Blundell and Harling P 3695 Valve sizing rule 5789 Log/tech slide chart
Blundell B.P - OIL Fuel Viscosity-Temp. 0497 Technical disc of PVC, 144x1 mm
Front Scales: 1) = 2) 3) = 4) 5) = 6) 7) 8) 9) 10)
Blundell Balloon BRL Mark IV A 0328 Meteorology slide rule of PVC, 628x62x12 mm
Front Scales: 1) 2) 3) 4) = K 6) 7) = 8) 9)
Blundell Bearing Rate Mark 1 Model 0 0496 Technical slide rule of PVC, 368x63x6.5 mm
Front Scales: 1) = 2) 3) = 4)
Blundell C 24 Face Cost & Profit Reckoner 2986 Slide rule of PVC
Blundell Cardiovascular Risk Calculator 0498 Medical disc of PVC, 127x1 mm
Front Scales: 1) = 2) + window
Blundell Conversion 0490.37 0503 Conversion slide chart of PVC, 190x77x2 mm (1994)
Front Scales: Side A: 20 scales
Back Scales: Side B: 180 mm 18 scales 7inch
Blundell DM 1 Rietz Instruction rule 2947 Generic slide rule of wood/plastic, 1520 mm
Front Scales: K A = B R C = D M
Back Scales: = S ST T =
Blundell E 13 c Electricians 2870 Electrical slide rule of PVC
Blundell E 25 C 3661 Technical slide rule of plastic, 289x41.5x8.5 mm
Front Scales: 25cm / LL2 A = B R C = D LL3 K #­V GEN. EFF. MOT. EFF. GEN. MOT.#, Back Scales: = sin lg tg =
Blundell E 25 Electricians 2983 Electrical slide rule of PVC
Blundell E 3 Electrical 2953 Electrical slide rule of bakelite
Blundell Exchange Rate converter 3158 Financial disc of plastic, 95x1.2 mm
Front Scales: 1) = 2) = 3)
Blundell F 5100 Black Body 3021 Radioactivity slide rule of PVC, 454x90x10 mm
Front Scales: g f 1) e = h j i l k m = d c b a
Back Scales: = n p o r q s =
Blundell FC 3540 Fisher Valve 0556 Log/tech slide rule of PVC, 330x46x4.5 mm (1967)
Front Scales: ­P %QC2 = P1 1) 2) 3) C1 Q = Cg %QC1
Back Scales: ­P %QC2 = P1 4) Q = Cv Cg
Blundell G 1 Students 2951 Generic slide rule of bakelite
Blundell G 2 0512 Generic slide rule of bakelite, 285x31x7.5 mm (1947-1949)
Front Scales: K A = B Rec C = D L
Blundell G 22/2 2918 Generic slide rule of PVC, 306x32x7 mm (1950)
Front Scales: A = B C = D
Blundell H Slide Rule 2993 Technical slide rule of PVC, 173x37x4 mm (1968)
Front Scales: 1 2 = 3 4 = 5 6 7 8
Back Scales: 9 10 = 11 12 = 13 14 15
Blundell Hercules C.Mk. 1
6B / 1112682
0515 Aviation disc of PVC, 178x2.5 mm
Front Scales: 1) 2) = 3)
Blundell Holophane Illumination Calculator 3148 Technical slide rule of bakelite, 290x49x8 mm
Front Scales: 1) 2) = 3) 4) 5) 6) = 7) 8)
Blundell Humidity 2906 Hydrology slide rule of PVC, 33.8x50x5 mm
Front Scales: (4) = (6)(5)(3) (3A) (2B)(2C) (2)(2A) = (1) (1B) (1A), Back Scales: (7)123 = C = D TA TB
Blundell Hygrorule 2693 Meteorology slide rule of PVC, 141x31x5 mm
Front Scales: 1) = 2) = 3), Back Scales: = 4) =
Blundell L 4 3017 Generic slide rule of bakelite, 284x32x8.5 mm (1947-1949)
Front Scales: U.L. A = B Rec C = D L.L.
Blundell L 6 0516 Generic slide rule of bakelite, 285x30x7 mm (1947-1949)
Front Scales: UL A = B Rec C = D LL
Back Scales: = S S&T T =
Blundell Lens Calculator 3157 Photography disc of plastic, 95x1.5 mm
Front Scales: 1) = 2) 3) = 4) = 5) 6)
Blundell Lens Calculator Osprey T.V. 0500 Technical disc of PVC, 86.5x1 mm
Front Scales: 1) 2) = 3) + 1 window with 4) + 5)
Blundell Lincoln MK. 2 1577 Aviation slide rule of bakeliteplastic, 343x63.5x10 mm
Front Scales: Many scales see picture
Back Scales: Many scales see picture page 2
Blundell Management Calculator 3160 Technical disc of plastic, 140x1 mm (1994)
Front Scales: 1) = 2)
Blundell MK 1 Lifeboat Sight Computer 9/4531 0520 Nautical slide chart of PVC, 280x80x25 mm (1956)
Front Scales: 1) 2) 3) = 4) =, Back Scales: = 4) =
Blundell MK 1 Mortar 81 mm 0526 Military disc of PVC, 127x1 mm (1988)
Front Scales: 0 1 2 3 4 5 6
Blundell Mk 2 Artillery Omega 10" Mils 0521 Generic slide rule of PVC, 298x42x8.5 mm (1958-1970)
Front Scales: 1/50000 / A = B C = D
Back Scales: = S ST T =
Blundell MK 3 Artillery 10" 0522 Generic slide rule of PVC, 299x41x8 mm (1958-1970)
Front Scales: A = B C = D, Back Scales: = S ST T =
Blundell MK 6 Humidity 0517 Technical slide rule of PVC, 287x47x9 mm
Front Scales: (4) = (5) (3) (3A) (2B) (2C) = (1) (1B) 1(A)
Back Scales: (7) 1) 2) = (6) (3) (3A) (2) (2A) =
Blundell N 52 (Navigator) Janus 0525 Generic slide rule of PVC, 330x55x5 mm
Front Scales: S1 A = B TA TB ST S C = D K L
Back Scales: 1) 2) 3) 4) 5) = 6) 7) CI 8) 9) C = D SM KM
Blundell NL 11 - 95 0523 Generic disc of PVC, 95x2 mm (1995)
Front Scales: L D = C CI A
Blundell O.S. 686 A Calculator 2921 Technical slide rule of PVC, 134x47x3.8 mm (1959)
Front Scales: 1) = 2) = 3)
Blundell P 10 3156 Generic slide rule of co-polymer, 160x33.5x6.5 mm (1948-1958)
Front Scales: 6inch / CUBE A = B REC C = D MAN
Back Scales: = S S&T T = 15cm
Blundell P 1365 Flow of Water in Pipes 2916 Technical slide rule of PVC, 175x47x3.8 mm
Front Scales: X = Y W = Z V
Blundell P 14 2977 Generic slide rule of co-polymer
Blundell P 15 2978 Generic slide rule of co-polymer, 160x32x4.2 mm (1948-1958)
Front Scales: 6inch / A = B REC C = D
Back Scales: = S S&T T = 15cm
Blundell P 1553 Armstrong Calculator 2811 Log/tech slide rule of PVC, 288x47x3.5 mm
Front Scales: S A = B P C = D F
Blundell P 1644 Armstrong Calculator 3407 Log/tech slide rule of PVC, 298x52x8 mm
Front Scales: 11inch / S A = B P C = D F
Back Scales: 1) 2)
Blundell P 17 0524 Generic slide rule of co-polymer, 160x33.8x4.6 mm
Front Scales: 6inch / U.L. A = B R C = D L.L.
Back Scales: = S. S.&T. T. = 15cm
Blundell P 1732 - A Fisher Valve Mark III 0547 Log/tech slide rule of PVC, 254x37x3.5 mm (1963)
Front Scales: VC ­P D = C 1) 2) Q = Cv 3) Kv
Back Scales: 4) P1 Pc = ­P 5) 6) 7) 8) Qs Qg = CG CS 9)
Blundell P 1843 Nunn Blood Gas Predictor 0548 Medical slide chart of PVC, 280x57x3 mm (1962)
Front Scales: 1) = 2) = 3) 4) 5) 6) = 7) 8) = 9)
Back Scales: = 10) = = 11) 12) 13) 14) = 15)
Blundell P 2297 Torpedo Spreading Slide Rule 3440 Military slide rule of plastic, 317x162x8 mm
Front Scales: 1) = 2) 3) = 4) 5) = 6) 7) = 8)
Blundell P 2808 Ultrasonic 0550 Log/tech slide rule of PVC, 184x65.6x8 mm (1967)
Front Scales: A = B C = D E = F G = H I
Back Scales: = J K = L M = N = O 5inch 12cm
Blundell P 3241 Rapid Glaze Calculator 0551 Technical disc of PVC, 144x2 mm (1969)
Front Scales: A C = B D
Blundell P 3259 0552 Technical slide rule of PVC, 343x49.5x3.5 mm (1969)
Front Scales: 10inch A B = C D E = F G 1)
Back Scales: 250 mm H I = J K L = M N O 2)
Blundell P 3357 Thermal Expansion of Pipelines 5396 Log/tech slide chart of plastic, 228x48x1.4 mm
Front Scales: See Picture, Back Scales: See Picture
Blundell P 3483 Tarrant Hydraulic Slide Rule 0555 Technical slide rule of PVC, 290x47x4 mm
Front Scales: 1) 2) 3) = 4) 5) 6) = 7)
Blundell P 3512 Textile 2992 Technical slide rule of PVC, 298x43x9 mm
Front Scales: 28cm = 1) = 2) te tb 3) = 4)
Blundell P 3706 Nylon Tube Friction Loss Calculator 3408 Log/tech slide rule of PVC, 338x49x4 mm
Front Scales: 1) = 2) 3) = 4)
Blundell P 3969-77 Textile 2961 Technical slide rule of PVC, 400x108x8.5 mm
Front Scales: 1) 2) 3) 4) = 5) 5) = 6) = 7) 8) = = 9) 10) 11) 12) = 13) 14) 15) 16)
Blundell P 4366 Ultrasonic 2912 Log/tech slide rule of PVC, 245x50x5 mm (1967)
Front Scales: E A D = C B F G = H I
Back Scales: 5inch 12cm L = K J N = M O
Blundell P 4463 Holophane Illuminance and Angle Calculator 2913 Technical slide rule of PVC, 320x37x4 mm
Front Scales: 1) 2) = 3) 4)5) 6) = 7) 8) 9)
Back Scales: 10) = 11) 12) = 13) 14)
Blundell P 4603 MK III Orifice Slide Rule 2915 Technical slide rule of PVC, 318x37x4 mm
Front Scales: m d/D = h rs = N
Back Scales: m d/D = hm Ss = Nm
Blundell P 4740 IFD Cell Reactor 2994 Technical slide rule of PVC, 650x133x8 mm
Blundell P 4743 Fisher Valve 2987 Log/tech slide rule of PVC, 330x46x4.5 mm (1976)
Front Scales: ­P %QC2 = P1 1) 2) 3) C1 Q = Cg %QC1
Back Scales: ­P %QC2 = P1 4) Q = Cv Cg
Blundell P 4843 Hydraulic 2920 Technical slide rule of PVC, 330x46x4 mm (9/78)
Front Scales: A B1 B2 = C2 C1 E2 1) 2) 3) E1 = H 4)
Back Scales: B1 B3 = D1 5) 6) D2 F2 F1 = J
Blundell P 5088 The H Slide Rule 0557 Technical slide rule of PVC, 328x46x4 mm (1968)
Front Scales: 1 2 = 3 4 = 5 6 7 8
Back Scales: 9 10 = 11 12 = 13 14 15
Blundell P 5527 Roof Pitch Indicator 5347 Technical slide chart of plastic, 94x103x1.7 mm (1995)
Front Scales: See Picture, Back Scales: See Picture
Blundell P 5597 Hydro Aluminium 0560 Technical disc of PVC, 178x1.5 mm
Front Scales: 1) = 2) + 2 windows
Back Scales: 3) 4) + 1 window
Blundell P 5637 BOC Hospitality Division 3159 Technical slide chart of plastic, 750x360x6 mm
Front Scales: 1) = 2) = 3) = 4) = 5) = 6) = 7)
Blundell P 5705 Torque Calculator 0561 Technical disc of PVC, 147x1.5 mm (1990)
Front Scales: 1) 2) = 3) 4) 5) = 2 windows
Blundell P 5709 Radiography Mk. VI 0562 Technical disc of PVC, 134x3 mm (1954)
Front Scales: 1) 2) = 3) 4) 5) 6) 7) 8) = 9) 10)
Blundell P 5731 Note Tracker 3426 Music slide chart of plastic, 280x115x1.5 mm
Front Scales: Many scales, Back Scales: Many scales
Blundell P 5798 BMI Calculator 0563 Medical disc of PVC, 95x1 mm (1992)
Front Scales: 1) = 2) = 3)
Blundell P 5852 Fuel Oil Preheat 0564 Technical disc of PVC, 156x1 mm (1993)
Front Scales: 1) = 2) 3) = 4) 5) = 6) 7) 8) 9) 10)
Back Scales: 11) = 9 windows
Blundell P 5897 Dalton Aviation Computer 0565 Aviation disc of PVC, 115x134x6 mm
Front Scales: 1) 2) 3) = 4) 5) + 4 windows + 6) 7)
Back Scales: 8) = 9) 10)
Blundell P 5931 Zeneca 3162 Log/tech disc of plastic, 89x210x1 mm
Blundell P 5939 Metric Imperial Price Converter 0502 Technical slide chart of PVC, 190x103x2.5 mm (1995)
Front Scales: Side A: 1) = 2) = 3) = 4) = 5) = 6) = 7) = 8) =, Back Scales: Side B: 9) = 10) = 11) = 12) = 13) = 14) = 15) = 16) =
Blundell P 8 0519 Generic slide rule of bakelite, 159x255x5 mm (1947-1949)
Front Scales: A = B CI C = D
Back Scales: 6inch = = 15cm
Blundell Paper Machine Production Calculator 3913 Log/tech slide rule of plastic, 232x52.5x2.5 mm
Blundell Photographic Interpreters MK II 2908 Photography slide rule of PVC, 335x50x5 mm
Front Scales: A = B CI ST C = D S TA TB
Back Scales: 1) 2) = 3) 4) 5) = 6)
Blundell Popular no. 1 3155 Generic slide rule of PVC, 284x42x3 mm
Front Scales: L K A = B CI C = D S ST T
Blundell Protractor, 6 inch Ivorine 'A' MK. IV 3146 Technical protractor of ivory/metal, 152x51x2 mm
Front Scales: Various see picture
Back Scales: Various see picture
Blundell Radiac no. 1 MK 2 2781 Military disc of PVC, 126x1.5 mm
Front Scales: 1) = 2) = 3)
Blundell Radiac Pat. No. 644944 0504 Log/tech slide rule of PVC, 300x66.5x9 mm
Front Scales: = A1 A2 = B1 B2 = C1 C2 = D
Back Scales: = F1 F2 = = E1 E2 =
Blundell Reproduction 0569 Log/tech disc of PVC, 126x1.3 mm
Front Scales: A = B 1)
Blundell S 100 3833 Generic slide rule of plastic, 139.5x27.5x4 mm
Front Scales: A = B C = D
Blundell S 125 3829 Generic slide rule of plastic, 151x32x2 mm
Front Scales: CUBE A = B REC. C = D MAN.
Blundell S 143 - 10 0528 Generic slide rule of PVC, 305x36x4 mm (1970-1982)
Front Scales: K A = B CI C = D L
Blundell S 143 - 10 (Factory model) 3163 For fabrication plate of metal, 1250x250x3 mm (1970-1982)
Front Scales: K A = B CI C = D L
Blundell S 143 - 20 0529 Generic slide rule of PVC, 172x36x4 mm
Front Scales: K A = B CI C = D L
Blundell S 143 / 5 E 2919 Generic slide rule of PVC, 149x27x2.8 mm (1970-1982)
Front Scales: K A = B CI C = D L
Blundell S 150 - 10 0495 Generic slide rule of PVC, 306x36.8x4 mm
Front Scales: S T A = B CI C = D K L
Blundell S 150 - 10 P (Projection) 2988 Generic projection of perspex, 366x56x5 mm
Front Scales: S T A = B CI C = D K L
Blundell S 150 - 10 Staedtler 3257 Generic slide rule of PVC
Blundell S 150 - 20 0530 Generic slide rule of PVC, 174x37x4 mm (1970-1982)
Front Scales: S T A = B CI C = D K L
Blundell Shackleton MR MK. 3 2344 Aviation slide rule of bakeliteplastic, 344x64.5x11 mm (1978)
Front Scales: Many scales see picture
Back Scales: Many scales see picture page 2
Blundell Students no. 1 3149 Generic slide rule of co-polymer
Blundell T 11 Technicians 2954 Slide rule of co-polymer
Blundell T 12 Technicians 2955 Generic slide rule of PVC
Blundell T 20 Technicians 2969 Generic slide rule of bakeliteco-polymer
Blundell T 50 Janus 2910 Generic slide rule of PVC, 341x45x5.2 mm (1952 1957-1965)
Front Scales: L P A = B T ST S = D DI K, Back Scales: LL01 LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL1
Blundell Tank Capacity Computer 3409 Log/tech slide chart of plastic, 187x48x2.2 mm
Front Scales: 1) 2) = 3) 4) = 5)
Blundell Turning guide Mitsubishi Carbide 3161 Technical disc of plastic, 146x1 mm
Front Scales: 1) 2) 3) 4)
Blundell U 7 2968 Generic slide rule of bakelite
Blundell V.F. 0129 0527 Generic slide rule of PVC, 285x36.5x6.4 mm
Front Scales: 10inch / A = B C = D
Back Scales: = S ST T =
Blundell Valve Sizing and Flow Foxboro 0506 Technical slide rule of PVC, 151x49x3.5 mm
Front Scales: A) = B) C) = E), Back Scales: = B C =
Blundell Vector Slide Rule 3419 Mathematics complex of plastic/metal
Blundell Victor K MK. 2 2636 Aviation slide rule of PVC, 342x63x10 mm
Front Scales: Many scales see picture
Back Scales: Many scales see picture page 2
Blundell Vulcan B. MK. 2 C.G. 0508 Aviation slide rule of bakeliteplastic, 342x63x10 mm
Front Scales: Many scales see picture
Back Scales: Many scales see picture page 2
Blundell Vulcan B/K. MK. 2 C.G. 0509 Aviation slide rule of bakeliteplastic, 342x63x10 mm
Front Scales: Many scales see picture
Back Scales: Many scales see picture page 2
Blundell W.H. Smith Log - log trig 0501 Generic slide rule of PVC, 330x46x4 mm (1970-1982)
Front Scales: K LL2 LL3 A = B L CI C = D S T ST
Blundell W.H. Smith Rietz 0507 Generic slide rule of PVC, 330x47x4 mm
Front Scales: L K A = B CI C = D S T ST
Blundell W.H. Smith Simplified Rietz 2911 Generic slide rule of PVC, 173x36x4.2 mm (1970-1982)
Front Scales: K A = B CI C = D L