submerged construction. Schilling took the project as far as ordering the submarine cable from a rope factory in St. Petersburg, but he died on 6 August (N.S.), and the project was subsequently cancelled. Single-wire code Schilling is sometimes credited with being the first to devise a code for a single-wire telegraph, but there is some doubt about how many needles he used and at what dates. It may be that Schilling used a single-needle-only setup on demonstrations around Europe merely for ease of transport, or it may have been a later design inspired by the Gauss and Weber telegraph, in which case he would not have been the first. The code alleged to have been used with this telegraph can be traced to Alfred Vail, but the variable-length code (like Morse code) given by Vail is merely shown as an example of how it could be used. In any case, two-element signalling alphabets predate any form of electrical telegraphy by some time. According to Hubbard, it is more likely that Schilling used the same code as used on the six-needle telegraph, but with the bits sent serially instead of in parallel. Automatic recording Schilling looked into the possibility of automatic recording of telegraph signals, but could not make it work due to the complexity of the device. His electrical engineering successor, Jacobi, succeeded in doing this in 1841 on a telegraph line from the Winter Palace to the General Staff Headquarters. Mines and fuses Another field of Schilling's research, directly related to telegraphy, was practical military applications of electricity for remote control of land and naval mines. In 1811 Johann Schweigger suggested the idea of exploding bubbles of hydrogen released from the electrolyte by passing electric current. Schilling discussed the idea with Sommering, and realised the military prospects for the invention. He devised a water resistant conducting wire that could be laid in wet earth or through rivers. It consisted of a copper wire insulated with a mixture of India-rubber and varnish. Schilling had in mind the military use of telegraphy in the field as well, and was excited about the prospects. Sömmerring wrote in his diary "Schilling is quite childish about his electro-conducting cord." In September 1812 Schilling demonstrated his first remote-controlled naval fuse to Alexander I on the Neva River in Saint Petersburg. The invention was intended for coastal defense and sieges, and was deemed unsuitable for the