Origins of a couple of well-worn phrases.

1. Keep it under your hat. I'm now reading Agincourt - Henry V and the Battle That Made England, by Juliet Barker (Little & Brown, 2005). At page 88, she describes the makings of the English long bow:

The best bow-staves were cut from a single piece of straight-grained yew, imported from Spain, Italy or Scandinavia, and shaved into shape. Unstrung, the bow would be some six feet long and tapered, with the softer, more flexible sap-wood on the outside and a thicker layer of heart-wood on the inside, a combination that gave the bow its natural elasticity. ... A regular maintenance regime of waxing and polishing ensured that the bow did not dry out or crack under the pressure of being strung or fired. Bow-strings, made of hemp or gut, were also waxed or oiled to keep them weather-proof, though this was not always successful. ... The English, perhaps because they were more accustomed to rain, had learned to deal with such possibilities. According to the French chronicler Jean de Vennette, they "protected their bows by putting the strings on their heads under their helmets," a habit that is said to have given rise to the expression "keep it under your hat."

2. Got the shaft. Nothing to do with bows or arrows. Paul Hoffman, late Lion's Head regular, wrote a book back in the early 1970's titled Lions in the Street - the Inside Stories of the Great Wall Street Law Firms. In his chapter on Simpson Thacher & Bartlett, he recounted the time when the firm had its offices in the old Equitable Building at 120 Broadway, which was built before air conditioning and consequently was designed in an "H" shape, with two large air shafts facing to the east and west. Anyway, the story went, when a lawyer fresh from law school started with the firm, he (as it almost always was in those days) was put in a "bullpen", a large room where he and other young associates had individual desks but otherwise shared space. After a few years, a winnowing would happen. The associates would be given individual offices. But, herein hangs a tale. Those who had been judged worthy of eventual partnership would be given offices with windows facing a street, while those destined to be asked to find other employment were given offices facing an airshaft. So, after these annual separations of the wheat from the chaff took place, word would rush throught the bullpen: "Did you hear about Joe? He got the shaft!"