b. 14 September 1847 Serdobsk, Russia
d. April 1894 St Petersburg, Russia
Jablochkoff studied at the Military Engineering College in St Petersburg. Having a scientific bent, he was sent to the Military Galvano Technical School. At the end of his military service in 1871 he was appointed Director General of the Moscow-Kursk telegraph lines for the Midi Railway Company. At this time he began to develop an interest in electric lighting, and in 1875 he left the Imperial Telegraph Service to devote his time exclusively to scientific pursuits. He found employment at the workshop of M Bréguet in Paris, where Gramme dynamos and Serrin arc lamps were being constructed. After some experimentation he found a means of producing a carbon arc that regulated itself without any mechanism. This lamp, the Jablochkoff candle, with two carbon rods placed parallel to each other and so close that an arc formed at the ends, could continue to burn until the rods were consumed. Plaster of Paris was used to separate the two electrodes and crumbled away as the carbon burned, thus exposing fresh carbon. These lamps were used in May 1878 in Paris to illuminate the avenue de l'Opéra, and later in Rome and London, and in essence were the first practical electric street lighting. Since there was no regulating mechanism, several candles could be placed in a single circuit. Despite inherent defects, such as the inability to restart the lamps after they were extinguished by wind or interruption of supply, they remained in use for some purposes for several years on account of their simplicity and cheapness. In 1877 Jablochkoff obtained the earliest patent to employ transformers to distribute current in an alternating-current circuit.
b. 4 April 1835 Providence Green, Yorkshire, England
d. 7 October 1911 London, England
Jackson studied medicine at York and at St Bartholomew's Hospital, qualifying in 1856. For a while he practised in York and was dissuaded from abandoning medicine for philosophy by Jonathan Hutchinson. Upon his return to London, he was appointed Assistant Physician and later, in 1874, Physician to the London Hospital. He was also on the staff of Moorfields Eye Hospital and in 1874 was appointed to the National Hospital for the Paralysed and Epileptic in Queen's Square. It was particularly in connection with his association with cases at the latter that he was able to establish the association of designated areas of the brain with specific limbs and functions. He acknowledged that in the field of speech the work of Broca had shown the way.
FRS 1878. Gulstonian Lecturer and Croonian Lecturer, College of Physicians.