An induction coil consists of two coils of insulated copper wire wound around a common iron core. One coil, called the primary winding, is made from relatively few (tens or hundreds) turns of coarse wire. The other coil, the secondary winding, typically consists of many (thousands) turns of fine wire. An electric current is passed through the primary, creating a magnetic field. Because of the common core, most of the primary's magnetic field couples with the secondary winding. The primary behaves as an inductor, storing energy in the associated magnetic field. When the primary current is suddenly interrupted, the magnetic field rapidly collapses. This causes a high voltage pulse to be developed across the secondary terminals through electromagnetic induction. Because of the large number of turns in the secondary coil, the secondary voltage pulse is typically many thousands of volts. This voltage is often sufficient to cause an electric spark, to jump across an air gap separating the secondary's output terminals. For this reason, induction coils were called spark coils. The size of induction coils was usually specified by the length of spark it could produce; an '8 inch' (20 cm) induction coil was one that could produce an 8 inch arc. (http://en.wikipedia.org/wiki/Induction_coil)A metal and plastic object on a timber stand. In an induction coil the distance between the plates is often used to measure the voltage of the spark since the air breaks down at 30 000 volts per centimetreballarat college of advanced education, scientific instrument, induction coil, scientific instruments, electricity

Induction Coil - used in lecture demonstrations

"Ford-Coil" (Induction coil) used with batteries for high tension induction

Induction coil, note ivory handles to spark adjusters. (said to have a tinfoil condenser)

Crystal radio set in hinged wooden box. Induction coil stands upright when box is opened. Has four aerial connections and rotatable connection for tuning the aerial. Appears to have been made commerciallycommunication, radio

According to 'Salute to the X-Ray Pioneers of Australia' the X-Rays experiments conducted at the Ballarat School of Mines 'played a conspicuous part in the development of the application for x-rays to medicine.' John M. Sutherland conducted most of the experiments with induction coils giving 6 inch, 12 inch and 16 inch sparks respectively. Photograph of a timber frame with 27 original X-Rays conducted by John Sutherland at the Ballarat School of Mines. X-Rays include human bones, kangaroo hand, steel, bent knee, gold in quartz, snake, and others.x-ray, john m. sutherland, ballarat school of mines, john mckenzie sutherland, xray, pioneer xrays

The 400 series telephone was developed by the PMG in 1957 and introduced into service in 1958 to replace the 300 Series telephones. This telephone series was based on the Ericsson/GEC 1000 type and designed to work on longer and lighter gauge cables (1000 ohm lines). It was fitted with a new 5 winding Induction Coil (Coil, Induction No. 21A), had a more efficient anti-sidetone circuit, a sensitive rocking armature receiver and a new style handset with no spittoon. The 400 Series included automatic (401, 404, 405 and 411), central battery (402, 406 and 407) and local battery/magneto (403) versions and was made as both table and wall models. The 410 was used on Shared Service. Initially it was intended that the 400 Series would be available in a range of colours but due to fading issues only black and ivory were eventually available to subscribers. There were several variants of the 400 Series and they were manufactured by Ericsson and GEC in England and by AWA in Australia. The Ericsson/GEC version used an internal chassis like the Telephone 332 or 332AT but the AWA version had all the main components mounted on the base plate. The initial APO instruction issued in 1958 showed the rounded GEC/Ericsson 1000 shape case as the new 400 series but the production models had the older 300 type case. The ivory 400 series was only available as a table model and was made by Ericsson. The wall models were only made by AWA Reference https://www.britishtelephones.com/aus/400type.htp.A black telephone with a with a metal dial with numbers 1 to 0 in the finger holes in the dial. A handset with a mouthpiece on one end and an earpiece on the other end sits on the top of the telephone and is attached to the telephone with a plastic black spring winded cord. A plastic brown cord with a white plug connects the telephone to a socket 400 telephone, dial telephone

X-Rays were first discovered on 8 November 1895. By 18 July 1896 staff members of the Ballarat School of Mines (SMB), were experimenting with the exciting new discovery. The history of x-rays began on 8 November 1895 at the University of Wurzburg in Bavaria. The discovery was officially announced on 25 December 1895. The first radiographs in Ballarat were taken at the School of Mines in July 1896 according to the Ballarat School of Mines (SMB) Annual Report. Frederick J. Martell, the Registrar of SMB arranged for the importation of tubes, while John M. Sutherland, an electrician, conducted most of the experiments giving 6 inch, 12 inch and 16 inch sparks respectively. In a short time brilliantly successful results were obtained, with some SMB Roentgen negatives taken at this time still in existence today. Samuel Ernest Figgis, H. R. W. Murphy, D. McDougall, and Frederick J. Martell carried out experiments at the SMB on Saturday evening 18 July 1896, producing 'perfect' negatives of a hand and wrist. A Roentgen Tube and an induction coil giving a two inch spark, the coil being sparked by the SMB's dynamo, were used to obtain these results. The Courier reported that 'the exposure of five minutes was ample' but concluded that 'the length of the exposure will be shortened as experiments proceed.' The Ballarat Courier reported on 20 July 1896 that: "Thanks to the energy of the staff of The School of Mines, Ballarat, and particularly to Messers F.J. Martell and D. McDougall, the assistance of Rontgen X-rays will soon be available, for the relief of suffering humanity, at this institution." Martell was an ardent amateur photographer, and Duncan McDougall's experience as an electrician has enabled the two gentlemen to carry their experiments on to a perfectly successful issue. At first these gentlemen, together with Professor Purdie and Mr W. Huey Steele, conducted a series of experiments by the aid of a Bonetti glass-plate induction machine which had been constructed by Mr McDougall. The results were very good, the various bones of the hand being distinctly visible. The following people were among those who witnessed the first X-ray experiments to be carried out in Ballarat. Andrew Anderson, President of the School of Mines, a large number of ladies and gentlemen, the medical profession Dr Edward Champion (1867-1929) Dr Gerald Eugene Cussen (1888-1943) Dr William Edward Davies (1868-1928) Dr Charles William Henry hardy (1861-1941) Dr Edward Kenneth Herring(1864-1922) Dr Joseph Lalor (1859-1907) Dr James Thomas Mitchell (1856-1945) Dr Edward Graham Ochiltree (1857-1896) Dr Robert Denham Pinnock (1849-1902) Dr Joseph Francis Usher (c1832-1909) Dr Grace Vale (nk-1933). The staff of SMB Professor Alfred Mica Smith Professor D. J. Dawbarn Mr. F. J. Martell. (http://guerin.ballarat.edu.au/aasp/is/library/collections/art_history/honour-roll/honourroll_X-Ray_pioneers.shtml)Two men, one seated, one standing standing in a room with early electrical equipment. They are conducting pioneer X-rays at the Ballarat School of Mines in 1896. Seated on the left is John Waters Sutherland.A bromide of this images states "Experimenting with X-rays, 1896"ballarat school of mines, x-ray, xray, john sutherland, sutherland, electricity, photography, foto, roentgen tube, medical

X-Rays were first discovered on 08 November 1895. By 18 July 1896 staff members of the Ballarat School of Mines (SMB), were experimenting with the exciting new discovery. The history of x-rays began on 08 November 1895 at the University of Wurzburg in Bavaria. The discovery was officially announced on 25 December 1895. The first radiographs in Ballarat were taken at the School of Mines in July 1896 according to the Ballarat School of Mines (SMB) Annual Report. Frederick J. Martell, the Registrar of SMB arranged for the importation of tubes, while John M. Sutherland, an electrician, conducted most of the experiments giving 6 inch, 12 inch and 16 inch sparks respectively. In a short time brilliantly successful results were obtained, with some SMB Roentgen negatives taken at this time still in existence today. Samuel Ernest Figgis, H. R. W. Murphy, D. McDougall, and Frederick J. Martell carried out experiments at the SMB on Saturday evening 18 July 1896, producing 'perfect' negatives of a hand and wrist. A Roentgen Tube and an induction coil giving a two inch spark, the coil being sparked by the SMB's dynamo, were used to obtain these results. The Courier reported that 'the exposure of five minutes was ample' but concluded that 'the length of the exposure will be shortened as experiments proceed.' The Ballarat Courier reported on 20 July 1896 that: "Thanks to the energy of the staff of The School of Mines, Ballarat, and particularly to Messers F.J. Martell and D. McDougall, the assistance of Rontgen X-rays will soon be available, for the relief of suffering humanity, at this institution." Martell was an ardent amateur photographer, and Duncan McDougall's experience as an electrician has enabled the two gentlemen to carry their experiments on to a perfectly successful issue. At first these gentlemen, together with Professor Purdie and Mr W. Huey Steele, conducted a series of experiments by the aid of a Bonetti glass-plate induction machine which had been constructed by Mr McDougall. The results were very good, the various bones of the hand being distinctly visible. The following people were among those who witnessed the first X-ray experiments to be carried out in Ballarat. Andrew Anderson, President of the School of Mines, a large number of ladies and gentlemen, the medical profession Dr Edward Champion (1867-1929) Dr Gerald Eugene Cussen (1888-1943) Dr William Edward Davies (1868-1928) Dr Charles William Henry hardy (1861-1941) Dr Edward Kenneth Herring(1864-1922) Dr Joseph Lalor (1859-1907) Dr James Thomas Mitchell (1856-1945) Dr Edward Graham Ochiltree (1857-1896) Dr Robert Denham Pinnock (1849-1902) Dr Joseph Francis Usher (c1832-1909) Dr Grace Vale (nk-1933). The staff of SMB Professor Alfred Mica Smith Professor D. J. Dawbarn Mr. F. J. Martell. (http://guerin.ballarat.edu.au/aasp/is/library/collections/art_history/honour-roll/honourroll_X-Ray_pioneers.shtml) "Seven patients of the doctors who were present were treated. In each case the patient was suffering from the effects of an old wound or some other injury to other a hand or foot. One patient, a boy had a finger broken some years earlier and when xray plate of the injury was developed it indicated plainly the fracture on one of the joints of the third finger. In another case a woman had a foot had a foot X-rayed and the photograph revealed the seat of an earlier imjury to it. Likewise an injury to the bones of a hand of an elderly man was revealed by an x-ray photograph. Every X-ray photograph that evening showed the importance of this new development in electrical science and the doctors present agreed the "the results of the experiments on their patients, by showing the exact seat of the injury and its present condittion, would materially assist them iin supporting cures." (Warren Perry, The Ballarat School of Mines and Industries Ballarat, p 146.)A number of photographic xrays as taken by the Ballarat School of Mines in 1896. The xrays include bones, hands, feet, shoes and more. ballarat school of mines, scientific equipment, x-ray, xray, photography, foto, roentgen tube