From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparative table of various radiator matrix types, detailing their performance, weight, and cost.
| Identifier | ExFiles\Box 150\3\ scan0110 | |
| Date | 4th January 1936 guessed | |
| MATRIX HEAT DISSIPATION PER SQ FT FRONTAL AREA HEAT DISSIPATION PER LB. WT. CORRESPONDING CRITICAL AIR TEMPS °C WT OF MATRIX LBS COST OF MATRIX £ - s - d 20/25 RR HEX (LATEST TYPE) 3.250" DEEP H₁ H₂ 32.5 36.5 4 - 12 - 5 25/30 MARSTON MK V 2.825" DEEP (PRESENT STD) 1.29H₁ 1.20H₂ 48.0 39.2 3 - 13 - 6 25/30 MARSTON MK VI 2.050" DEEP LIGHTENED CONSTRUCTION 1.40H₁ 1.76H₂ 52.0 29.0 3 - 9 - 0 P II RR HEX (LATEST TYPE) 4" DEEP H₃ H₄ 35.0 50.0 7 - 13 - 4 P III MARSTON MK VI PRESENT STANDARD 1.21 H₃ 1.15H₄ 30.0 52.7 5 - 15 - 6 P III MARSTON MK VI LIGHTENED CONSTRUCTION 1.21H₃ 1.37H₄ 30.0 44.3 5 - 8 - 6 | ||