Commonly employed materials include aluminium, iron, steel, nickel alloys, and copper alloys. This casting process is advantageous for very complex castings, that would regularly require cores. It is also dimensionally accurate, requires no draft, and has no parting lines so no flash is formed. As compared to investment casting, it is cheaper because it is a simpler process and the foam is cheaper than the wax. Risers are not usually required due to the nature of the process; because the molten metal vaporizes the foam the first metal into the mold cools more quickly than the rest, which results in natural directional solidification. The two main disadvantages are that pattern costs can be high for low volume applications and the patterns are easily damaged or distorted due to their low strength. If a die is used to create the patterns there is a large initial cost. The first patent for an evaporative-pattern casting process was filed in April 1956, by H.F. Shroyer. He patented the use of foam patterns embedded in traditional green sand for metal casting. Frenches Ravine, California  Frenches Ravine is a former settlement in Yuba County, California. It was located south-southeast of Dobbins, at an elevation of 531 feet (162 m). It still appeared on maps as of 1895. Galena Hill, California  Galena Hill is a former settlement and mining camp in Yuba County, California. It was located north of Camptonville, an elevation of 2815 feet (858 m). It still appeared on maps as of 1895. The place takes its name from a group of miners from Galena, Illinois who struck gold here in 1852. Garden Valley, Yuba County, California  Garden Valley is a former settlement in Yuba County, California. It was located west-southwest of Camptonville, at an elevation of 1909 feet (582 m). It was inundated by Bullards Bar Reservoir. Honkut, California  Honkut (also, Hoan-kut, Hoancuts, and Honcut) is a former Maidu settlement in Yuba County, California. It was located near the mouth of Honcut Creek; its precise location is unknown. Lasslys, California  Lasslys is a former settlement in Yuba County, California. It was located west of Woodleaf, at an elevation of 2697 feet (822 m). It still appeared on maps as of 1897. Eliza Tibbets  Eliza Tibbets (born Eliza Maria Lovell; 1823–1898) was among early American settlers and founders of Riverside, California; she was an activist in Washington, D.C., for progressive social causes, including freedmen's rights and universal suffrage before going to the West Coast.