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

Footprint Tools is a hand tool manufacturer based in Sheffield, England. In 2014 most of their hand tools were still made in Sheffield at the Footprint factory. Footprint Tools can trace its manufacturing history as far back as the 1760s when Alfrid Ridge & Sons was established as a manufacturer of woodworking tools. Ridge was bought by the current owning family in 1932. The Footprint brand originates from 1875 when Thomas R Ellin, a member of a cutlery manufacturing family, started a tool manufacturing business under the brand "Footprint". This subsequently became known as Thomas R Ellin (Footprint Works). This company was bought by the current owning family in 1948 and began to manufacture a range of tools under the Footprint, Domino, Climax, John Bull, and Clinker brands. During World War 2 the divisions of the business were engaged in manufacturing hand tools for British and Commonwealth forces. After the war Footprint continued to grow, manufacture, and expand its range of hand tools for the professional tradesman. In 2008 Footprint moved to a larger factory and invested in new forging equipment, but this process was interrupted by a global recession, and Footprint was unable to generate enough business to cover the cost of the upgrades. In early 2009 the company was forced to liquidate and lay off its staff to pay creditors. The Jewitt family retained the brand and intellectual property, and later that year revived the company under the name Footprint Sheffield and began producing a smaller range of products at first. With the same family of owner-managers, now run by the fourth generation, in 2015 Footprint continues to manufacture most of their products in Sheffield, England, and exports worldwide.This item gives us a look into the history of the beginnings of an early company that made tools in Sheffield England and is still producing tools today.Ring Auger, Double Twist with Lead Screw, bit 1" with round shaft Imprinted 'footprint' trademarkflagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village

Footprint Tools is a hand tool manufacturer based in Sheffield, England. In 2014 most of their hand tools are still made in Sheffield at the Footprint factory. Footprint Tools can trace its manufacturing history as far back as the 1760s when Alfrid Ridge & Sons was established as a manufacturer of wood working tools. Ridge was bought by the current owning family in 1932. The Footprint brand originates from 1875 when Thomas R Ellin, a member of a cutlery manufacturing family, started a tool manufacturing business under the brand “Footprint”. This subsequently became known as Thomas R Ellin (Footprint Works). This company was bought by the current owning family in 1948 and began to manufacture a range of tools under the Footprint, Domino, Climax, John Bull and Clinker brands. During World War 2 the divisions of the business were engaged in manufacturing hand tools for British and Commonwealth forces. After the war Footprint continued to grow, manufacture and expand its range hand tools for the professional tradesman. In 2004, Footprint cooperated with the University of Sheffield in a study of modern manufacturing techniques. In 2008 Footprint moved to a larger factory and invested in new forging equipment, but this process was interrupted by a global recession, and Footprint was unable to generate enough business to cover the cost of the upgrades. In early 2009 the company was forced to liquidate and lay off its staff in order to pay creditors. The Jewitt family retained the brand and intellectual property, and later that year revived the company under the name Footprint Sheffield, and began producing a smaller range of products at first. With the same family of owner managers, now run by the fourth generation, in 2015 Footprint continues to manufacture most products in Sheffield, England and exports worldwide.A tool that was made by a UK company in the 1950s that has a long history of tool manufacture and after many changes in company ownership is still producing tools today in Sheffield England.Screw driver wooden handle turned and steel blade. Made in Sheffield by Alfrid Ridge and Son. London patternNoneflagstaff hill, warrnambool, shipwrecked-coast, flagstaff-hill, flagstaff-hill-maritime-museum, maritime-museum, shipwreck-coast, flagstaff-hill-maritime-village, screw driver, alfrid ridge & son, footprint tools, tools

Guest speaker Chad Griffiths (at 0:18:30), a former planning manager with 17 years' experience at Nillumbik Shire Council discusses what can and cannot be done with the Eltham War Memorial and former Shire Office sites. Guest speaker Andrew Lemon, Historian, former President of the Royal Historical Society of Victoria and a former board member of Heritage Victoria (0:46:45), discusses the unique aspects of the Eltham War Memorial site and the current submission to Heritage Victoria and process for heritage listing protection. Note: Andrew Lemon's presentation was interrupted between 1:05:00 to 1:06:10 and again at 1:08:00 to 1:11:40 due to a medical emergency involving a member of the audience.1:44:33 duration Digital MP3 File 36.8 MB 895 main road, 903-907 main road, agm, andrew lemon, chad griffiths, community meeting, ecag, eltham activity centre, eltham community action group, eltham pre-school, eltham shire office, eltham war memorial, eltham war memorial hall, infant welfare centre, nillumbik shire council, precinct 3, precint 4, senior citizen's centre