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With the possible exception of barrage balloons, the Zeppelin was the most cumbersome aircraft ever designed, but the bloated nature of the dirigible was the very means by which it could ascend to a ceiling of 8000 metres and remain at that altitude for up to four days – far higher and far longer than any conventional propellor-driven war plane.

However, the Zeppelin was hardly the most aerodynamic or safest contraption and therefore required a more scientific instrument than a basic altimeter. At least two or three altigraphs such as the example illustrated right, consigned to Bosleys' sale of military antiques in Marlow on April 14, were fitted to each aircraft. Not only did they measure how quickly the craft could ascend to or descend from a certain altitude, but also gauged the highest level which could be maintained without jeopardizing stability.

Bosley’s altigraph was in working order, the inspection sheet indicating it was last checked on June 19, 1918 and the cylinder mechanism housed in a polished mahogany case marked L63. Records state that Zeppelin L63 was first launched on March 4, 1918 under the command of Kaptain von Freudenreich and completed 39 flights before she was sabotaged at Nordholz in June 1919 to prevent the Allies from discovering her workings. This altigraph was a remarkable survival and attracted worldwide interest at Bosley’s sale – selling to an overseas collector of Zeppelin memorabilia at £2400.