Experience, both with models 5 and 6, and with the quarter-size model, had also demonstrated the necessity of providing some means whereby the aerodrome frame would be relieved of the torsional strains produced upon it by a side wind striking the under surface of the wings when the aerodrome was mounted on the car preparatory to a test. The means for preventing these torsional strains in the case of the models, when “overhead” type of launching car was used, has been described in Chapter X of Part I. However, with the “underneath” type of launching car, a different means was necessary. A plan, in which outriggers projected from the body of the car and wires running from these outriggers up to the main ribs of the wings, with means for releasing the wires just before the car reached the end of the track, was used with the “underneath” car in the tests of models 5 and 6 in the summer of 1899, but the outriggers were frequently deranged by the sudden stopping of the car at the end of the run and they were replaced by a simpler arrangement. In this plan the torsional strains were relieved by providing, at the forward and rear ends [p159] of the car, smaller hinged uprights furnished in their upper part with a small slot into which a pin projected from the bottom of the forward and rear guy-posts, respectively. The guy-wires from wings being connected to the lower ends of the guy-posts the torsional strain produced by a side wind was immediately transmitted from the wings through the guy-wires to the guy-post, whence it was transmitted to the car itself, and thus prevented from acting on the metal frame of the aerodrome, as shown in Plate 39. These additional short struts for taking up the torsional strain were first added to the small launching car in 1901, and in the succeeding tests made with the quarter-size model no trouble of any kind was indicated as likely to be caused by them. As it was these extra struts which were directly responsible for the accident in the launching of the large aerodrome October 7, 1903, at the time of its first trial, and possibly also for that on December 8, 1903, at the time of the second trial, special attention is here called to them.