AN HISTORICALLY IMPORTANT PROTOTYPE DESIGN MODEL FOR THE VAR...

Hammer

£900

AN HISTORICALLY IMPORTANT PROTOTYPE DESIGN MODEL FOR THE VARIABLE-PITCH AVIATION PROPELLER MADE BY WALLACE TURNBULL, CIRCA 1927

constructed with a lathe-turned hub and hand-sawn blade grips with square-ended hand-carved wooden blades bolted through -- 24¼in. (61.5cm.); together with an indenture signed by Turnbull's executors approving probate.

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Wallace Rupert Turnbull (1870-1954); found on the mantlepiece of his house when the estate in New Brunswick was sold in 1956 to the Steele family and thence by descent.

A mechanical engineering graduate of Cornell University, Turnbull was employed by Frederick & Co aircraft builders during the Great War and for who he invented several propeller types - the vari-pitch however was by far his most successful and important and is now the standard type of propeller used. The lot offered here was found on the mantlepiece of his old home after his death, it seems highly likely that he kept this memento of his most significant contribution to aviation as a memento but which was over-looked by his family when they sold the estate a couple of years later. The next owners luckily preserved it and so, nearly a century after its invention, the prototype for the first vari-pitch propeller is offered for sale.

Untouched, action seized, a remnant of sealing wax to one blade suggesting either balancing or a lost label, old wear commensurate with age.