This apparatus has up till now not become known. The assertion that the troublesome experiments had brought us year after year nearer to the solution of the difficulties, is quite inappropriate. Just the opposite is the case; they have taken us year after year further away from the solution, until at last all was thrown overboard and a new commencement made. Profs. Rühlmann[12] and Esson[13] also gave vent to their opinions against the connection of transformers in parallel. In a like manner Messrs. Gaulard and Gibbs for some time after the Zipernowsky-Déri system was known pleaded for their own method of connection, until at last they were obliged, on account of the unpleasant experiences at the Grosvenor Gallery in London, to adopt the system of parallel connection, which they then at once employed at Tours. There were, up till very lately, still many electricians who did not perceive the advantages of parallel connection, just for the simple reason that they were ignorant of the properties of the non-polar transformer, suiting the parallel system of connection for a rational system of distribution. Especially the one property of transformers remained unknown to the literature devoted to the subject up to the year 1885, namely, that in transformers properly constructed the relation between the primary electromotive force and that of the secondary, remains unaltered notwithstanding any variations in the current taken out; also that if the primary electromotive force be kept constant the secondary would likewise remain constant, provided the transformer be connected in parallel. It had taken 30 years, until at last the way was found leading to the desired result. We have already superabundantly explained that this direction was essentially different from that taken by all electricians until after Gaulard’s time; that not only the methods of connection, disposition, and regulation of the system, but also the construction of the transformers themselves had to be quite departed from, and apparatus constructed which obeyed totally other laws to those of the earlier forms. If indeed earlier inventors proposed for other purposes magnetically-closed induction coils, the fame due to the birth of proper non-polar transformers, in which the whole of the primary and secondary turns have a like position relatively to the magnetic-field, first invented, carried out, and combined into a self-regulating system of current distribution, belongs undoubtedly to Messrs. Zipernowsky, Déri, and Bláthy.