Horsetail Fall (Yosemite) Horsetail Fall (Yosemite) Horsetail Fall, located in Yosemite National Park in California, is a seasonal waterfall that flows in the winter and early spring. The fall occurs on the east side of El Capitan. If Horsetail Fall is flowing in February and the weather conditions are just right, the setting sun illuminates the waterfall, making it glow orange and red. This natural phenomenon is often referred to as the "Firefall", a name that pays homage to the manmade Firefall that once took place in Yosemite. This waterfall descends in two streams side by side, the eastern one being the larger
Tullgren funnel Antonio Berlese described this method of dynamic sampling in 1905 with a hot water jacket as heat source. In 1918 Albert Tullgren described a modification, where the heating came from above by an electric bulb and the heat gradient was increased by an iron sheet drum around the soil sample. Today's extraction funnels of this type usually combine elements from both publications and thus should be referred to as Berlese-Tullgren funnel. A variation of the Berlese funnel uses naphthalene flakes or similar aromatic mothballs in place of the heat source to drive organisms downward. This method finds application in situations