or hackles. On ceremonial occasions the helmet was topped with a spike (for infantry and cavalry regiments, for the Army Ordnance Corps and the Royal Engineers) or a ball (for the Royal Artillery and other corps); and general officers, staff officers and certain departmental officers, when in full dress, wore plumes on their helmets, similar to those worn on their full-dress cocked hats. George Orwell, commenting on the unproblematical use of slouch hats by Second World War British troops rather than the "essentially superstitious" use of pith helmets, wrote "When I was in Burma I was assured that the Indian sun, even at its coolest [even in the early morning, and the sunless rainy season], had a peculiar deadliness which could only be warded off by wearing a helmet of cork or pith. 'Natives', their skulls being thicker, had no need of these helmets, but for a European, even a double felt hat was not a reliable protection." The British Army formally abolished the tropical helmet (other than for ceremonial purposes) in 1948. The Ethiopian Imperial Guard retained pith helmets as a distinctive part of their uniform until the overthrow of Emperor Haile Selassie I in 1974. Imperial Guard units serving in the Korean War often wore these helmets when not in combat. American naval officers could wear a pith helmet with the tropical khaki uniform. Most often the pith helmet was worn by the U.S. Navy's Civil Engineer Corps. Public use Through the first half of the 20th century, the Wolseley pattern helmet was routinely worn with civil uniform by British colonial, diplomatic and consular officials serving in 'hot climates'. It was worn with a gilt badge of the royal arms at the front. When worn by governors and governors-general, the helmet was topped by a 10-inch red and white swan-feather plume. British diplomats in tropical postings, governors-general, governors and colonial officials continued to wear the traditional white helmets as part of their ceremonial white uniforms until Foreign and Commonwealth Office officials ceased to wear such dress in the late 20th century as an economy measure. The ceremonies marking the end of British rule in Hong Kong in 1997 featured the Royal Hong Kong Police Aide-de-camp to the Governor in a white Wolseley pith helmet with black and white feathers, and was probably the last occasion on which this style of headdress appeared as a symbol of Empire. Civilian