Secondly, referring to the lift, this constructional figure indicates the relative useful or pay loads carried with the smallest amount of material used in the ship itself, because the ship, which must also be carried is “dead weight.” As we must consider all ships equal as far as structural safety is concerned, the technical performance is determined by judging the relative performance in carrying useful loads (for ships of similar size), or equal loads with smaller ships, which means economy of operation. The higher figure indicates superior quality. It should be noted that this constructional figure is applicable only to comparison of airships of similar size, speed and service requirements. For general comparison, however, ships of approximately the same size may be considered. Thirdly, all-around efficiency (the combined quality figure) is somewhat arbitrarily chosen by considering both the speed and carrying qualities together. It is not based on scientific deduction, but rather is a practical means of estimating general worth, as speed and carrying capacity are the main requirements of an airship. [PLATE 27: Zeppelin-Dornier “Komet” All Metal Monoplane, Type DoCIII, 1920 Model. Zeppelin-Dornier “Komet” All Metal Monoplane. Carries six passengers besides pilot and mechanician. One motor of 185 horsepower.] Efficiency Characteristics of Some of the Latest and Best Airships of All Nations ===========+=======================+========+========+======+======+===== | | | | Efficiency | |Capacity|Maximum +------+------+----- Nationality| Type and Name | Cubic | Speed, | | | | | Meters | Miles |Speed | Lift |All- | | | per | | |round | | | Hour | (1) | (2) |(3) -----------+-----------------------+--------+--------+------+------+----- Non-Rigid Airships -----------+-----------------------+--------+--------+------+------+----- American | Goodyear Pony Blimp | 990 | 40 | 24.2 | 0.60 | 15 French | Caussin T 2 | 9120 | 57.5 | 28.0 | 0.85 | 24 British | NS | 10200 | 57.2 | 25.6 | 0.65 | 17 German | PL27 | 31300 | 55.7 | 27.0 | 0.98 | 26 Italian | T 34 (Roma) | 34000 | 74.2 | 21.5 | 0.68 | 15 -----------+-----------------------+--------+--------+------+------+----- Rigid Airships -----------+-----------------------+--------+--------+------+------+----- British | R 80 | 34000 | 59.7 | 36.6 | 0.80 | 29 British | R 33—R 34 | 55500 | 59.7 | 37.3 | 0.75 | 28 British | R 36—R 37 | 59500 | 65.0 | 40.0 | 0.80 | 32