John Fraser (botanist) of botany and natural science." Species named after Fraser include, among others, "Abies fraseri" (Fraser Fir), "Magnolia fraseri" (Fraser Magnolia), and the gentianworts, "Frasera". A 50-foot Fraser Fir was used in 1998 as the U.S. Capitol Christmas Tree; the species was also used in 1974. The Fraser's Saint John's wort ("Triadenum fraseri") is named in honour of Fraser. John Fraser's letters are maintained at the Royal Society of Arts, and one of his portraits hung at the Hunt Library. Both Hoppner and Raeburn painted his portrait. Fraser was an elected fellow of both the Linnean Society of London (FLS 1810)
Fraser Filter Fraser Filter A Fraser Filter, named after Douglas Fraser, is typically used in geophysics when displaying VLF data. It is effectively the first derivative of the data. If formula_1 represents the collected data then formula_2 is the average of two values. Consider this value to be plotted between point 1 and point 2 and do the same with points 3 and 4: formula_3 If formula_4 represents the space between each station along the line then formula_5 is the Fraser Filter of those four values. Since formula_6 is constant, it can be ignored and the Fraser Filter considered to be formula_7.