volts. An estimated 3,000 human fatalities were caused by the fence, as well as the destruction of livestock. Electric fences were used to control livestock in the United States in the early 1930s, and electric fencing technology developed in both the United States and New Zealand. An early application of the electric fence for livestock control was developed in 1936–1937 by New Zealand inventor Bill Gallagher. Built from a car ignition trembler coil set, Gallagher used the device to keep his horse from scratching itself against his car. Gallagher later started the Gallagher Group to improve and market the design. In 1962, another New Zealand inventor, Doug Phillips, invented the non-shortable electric fence based on capacitor discharge. This significantly increased the range an electric fence could be used from a few hundred metres to 35 km (~20 miles), and reduced the cost of fencing by more than 80%. The non-shortable electric fence was patented by Phillips and by 1964 was manufactured by Plastic Products, a New Zealand firm, under the name "Waikato Electric Fence". Since then, a variety of plastic insulators are now used on farms throughout the world. By 1939, public safety concerns in the United States prompted Underwriters' Laboratories to publish a bulletin on electric shock from electric fences, leading to the ANSI/UL standard No. 69 for electric fence controllers. In 1969 Robert B. Cox, a farmer in Adams County, Iowa, invented an improved electric fence bracket and was issued United States Patent No. 3,516,643 on 23 June 1970. This bracket improved electric fences by keeping the wire high enough above the ground and far enough away from the fence to permit grass and weeds growing beneath the wire to be mowed. The brackets attached to the posts by what may be called a "pivot bind" or "torsion-lock". The weight of the bracket, the attached insulator and the electric wire attached to the insulator bind the bracket to the post. Electric fences have improved significantly over the years. Improvements include: Polyethylene insulators replacing porcelain insulators, beginning in the 1960s. Polyethylene is much cheaper than porcelain and is less breakable. Improvements in electrical design of the fence energizer, often called a "charger" (USA) or "fencer" (UK). Changes in laws. In some jurisdictions, certain types of electrical outputs for fences were unlawful until the 1950s or 1960s. In other areas, signage requirements and other restrictions limited usability. Many US cities