In the past, left-handed children were made to write with their right hands. Why was left-handedness seen as a bad thing?

Not bad, but inconvenient and potentially limiting. We write from left to right. Before the development of ball points all writing was done with steel nibbed pens, which work by being dragged over the surface of the paper. Left-handers can only push them.

Don Thompson, Guildford

As a left-handed pupil at a primary school in the mid-1940s we were expected to write legibly with pen and ink. If you tried doing this with your left hand it would always smudge the wet ink. So you were forced to write right-handed or you developed a writing style that kept your left wrist well away from the fresh writing. It was worse at university reading civil engineering where the key drawing tool was a T-square that only came in a right-handed version!

Alastair Dick, Leatherhead, Surrey

Left-handedness was seen as an inconvenience by teachers; it was easier for a right-handed teacher to teach a right-handed child to write than a left-handed one. I attended primary school in the early 1960s, and my mother once stormed down to my school in great indignation when I announced that a teacher had made me write with my right hand; she later told me that forcing a child to use the non-favoured hand could result in the development of a stammer.

Fiona Crawford, Heslington, York

Why do my fingernails grow more quickly than my toenails?

Fingernails grow more quickly than toenails due to circulation. Blood flows more efficiently to the upper than the lower body.

Martin Hasseck, London

In the 1950s and 1960s in London large blue-black vans with darkened windows, full of enthusiastic truncheon-equipped policeman, were usually sent to the local boozer in the event of a closing-time punch-up. These were commonly known as Black Mariahs — where did this nickname originate?

Brewer’s Dictionary of Phrase and Fable traces the usage back to Boston in the 1840s, suggesting that the name derived from one Maria Lee, the large, black keeper of a lodging house in the city. She was allegedly of such a size that the police would call on her to help to subdue malefactors and take them in to custody.

Graham Thorne, Maldon, Essex

When were dust jackets for books introduced?

Dust jackets for books were introduced very soon after dust was invented.

Pete Webb, Hayfield, High Peak