THE Paris International Trade Fair will be held during May 13-29. An interesting feature is the Inventions Competition (Concours d'Inventions), which is open and free to every inventor. An invention of any type may be entered. It may take the form of a new apparatus or device or it may be an improvement which can be incorporated in existing machinery or material. There is a strict limitation that the invention must not have been exhibited for any other competition. Each competitor must also attach to his entry form a copy of his patent specification, or, if the invention be not patented, a notice setting forth its aims and functions and, when possible, a résumé of its technical qualifications. If possible, actual models (in working order) are to be submitted, but if this cannot be done, permission may be obtained for their presentation by means of a plan. The jury decides whether the plan submitted is sufficiently explicit in itself to convey to experts, and to the public, a clear representation of the functions and operation of the invention. The total area allotted to each exhibit will as a rule not exceed one square metre, but by special application to the committee larger models may be exhibited. All inventions entered for the competition are displayed in a special hall for the duration of the Fair and should be forwarded so as to arrive not later than May 5, addressed Foire de Paris, Concours d'Inventions, Porte de Versailles, Paris 15. The exhibits are classified under many headings, including engineering, medical apparatus, domestic economy, games, travel and camping, office equipment, publicity and education. Competitors whose inventions are not patented may apply for a certificate of guarantee affording protection in France for a period of twelve months from the opening date of the Fair. Entry forms can be obtained at the London Office of the Foire de Paris, 17 Tothill Street, Westminster, S.W.I, and must be completed by March 31.