One of the main causes of aeroplane accidents has been the breakage of some part of the machine while in the air, due to defective work in its construction. There is no doubt that air-craft are far more trustworthy now than they were two or three years ago. Builders have learned from the mistakes of their predecessors as well as profited by their own. After every serious accident there is an official enquiry as to the probable cause of the accident, and information of inestimable value has been obtained from such enquiries. The Royal Aero Club of Great Britain has a special "Accidents Investigation Committee" whose duty it is to issue a full report on every fatal accident which occurs to an aeroplane in this country. As a rule, representatives of the committee visit the scene of the accident as soon as possible after its occurrence. Eye-witnesses are called before them to give evidence of the disaster; the remains of the craft are carefully inspected in order to discover any flaw in its construction; evidence is taken as to the nature and velocity of the wind on the day of the accident, the approximate height at which the aviator was flying, and, in fact, everything of value that might bear on the cause of the accident. As a good example of an official report we may quote that issued by the Accidents Investigation Committee of the Royal Aero Club on the fatal accident which occurred to Colonel Cody and his passenger on 7th August, 1913. "The representatives of the Accidents Committee visited the scene of the accident within a few hours of its occurrence, and made a careful examination of the wrecked air-craft. Evidence was also taken from the eye-witnesses of the accident. "From the consideration of the evidence the Committee regards the following facts as clearly established: "1. The air-craft was built at Farnborough, by Mr. S. F. Cody, in July, 1913. "2. It was a new type, designed for the Daily Mail Hydroplane Race round Great Britain, but at the time of the accident had a land chassis instead of floats. "3. The wind at the time of the accident was about 10 miles per hour. "4. At about 200 feet from the ground the air-craft buckled up and fell to the ground. A large piece of the lower left wing, composing the whole of the front spar between the fuselage and the first upright, was picked up at least 100 yards from the spot where the air-craft struck the ground. "5. The fall of the air-craft was broken considerably by the trees, to such an extent that the portion of the fuselage surrounding the seats was practically undamaged. "6. Neither the pilot nor passenger was strapped in. "Opinion. The Committee is of opinion that the failure of the air-craft was due to inherent structural weakness. "Since that portion of the air-craft in which the pilot and passenger were seated was undamaged, it is conceivable their lives might have been saved had they been strapped in."