What is the origin of the phrase “cut the mustard”?

In the “olden days” migrant workers at harvest times would go from farm to farm and offer their services and the farmer would ask “Can you cut the mustard?”; ie, is your cutting tool good enough to cut the mustard, so the expression “Can you cut the mustard” means “Can you do the job?”

D. Marcelli, Sunninghill, Berks

It seems the phrase has a US origin and was first recorded in 1907 in a story by O. Henry, but its basis is uncertain. Some say that it’s a corruption of the military phrase “to pass muster”, indicating that military standards have been achieved. Others say that a cowboy expression “the proper mustard”, meaning the genuine thing, may be the basis — in the 19th century the word “mustard” was used in the US to imply excellence. “As keen as mustard”, dating from the mid-1600s, has also been suggested.

Dr James Briggs, Westbury-on-Trym

How much variation is there in the number of daylight hours in different parts of the UK? Is there any significant North-South variation at certain times of year?

Day length varies with latitude and season. In midsummer, day length at 50°N on the Lizard peninsula, Cornwall, is 16.3 hours, while at 60°N on Shetland it is 19 hours. In midwinter, day length on the Lizard is 8 hours, while on Shetland it is 6 hours. So northerly latitudes have longer summer days and shorter winter days.

Tony Baines, Bideford, Devon

This depends on the times of sunrise and sunset, which are dependent on one’s latitude and on the time of year. Near the equinoxes (mid-March, mid-September) the differences are insignificant. Everybody gets about 12¼ hours from sunrise to sunset, and twilight adds about 80 minutes for all parties.

Michael Spencer, Pittenweem, Fife

How do TV or film cameras film someone looking into a mirror without appearing in view?

If the camera looks directly over the actor’s shoulder then it will indeed be in its own shot. Its line of view has to be at a slightly greater angle to the mirror. Imagine the set in plan view, draw a straight line from the actor’s nose to the mirror and another from the camera’s lens to the same point on the mirror, keeping symmetry. The actor, looking down his line, sees the camera reflected in the mirror. The camera, looking down its line, sees the actor’s reflection.