Florida’s oldest teacher might be going great guns at 86, but an Essex man is still taking on supply work at the grand old age of 90.

Donald Turner (pictured above) spent most of his life working as an industrial chemist. But, finding himself between jobs in the 1950s, he tried his hand at supply teaching.

He enjoyed working with children so much that when he finally retired from industry at the end of the 1970s, he decided to return to the classroom as a way of supplementing his pension, and accepted a 12-month contract teaching four days a week at a local school.

At the end of that year, Mr Turner signed up as a supply teacher. He was now in his late sixties, yet he soon found himself in demand all over south Essex. “I don’t want to blow my own trumpet,” he says, “but I get on well with kids, particularly primary school kids. They enjoy me.

“I’ve known schools where the kids have said to the head, ‘If you need a supply teacher, call Mr Turner again please’. Some have said they wished I could come back because I have explained things better than their regular teacher.”

It was 1930 when Mr Turner left the City of London school. But his father couldn’t afford university, so he took a day job and did evening classes at West Ham municipal college, eventually qualifying as a chartered chemist.

Unsurprisingly, he specialises in teaching science, and loves nothing more than demonstrating centrifugal force with a length of string and two tin cans, or taking tadpoles into a classroom in the spring to explain about the life cycle of the frog.

But as a keen dancer who goes to ballroom sessions twice a week, he also enjoys giving children a taste of line dancing. (“They love ‘Mambo Number 5’, although they weren’t too keen when I tried to teach them ballroom.”) Mr Turner is still remarkably fit, although he admits he sometimes gets out of breath going up stairs and can no longer do everything he would like to.

“I still swim, about once every three weeks,” he says. “I can do a quarter of a mile, but it takes me nearly 20 minutes now.” And although he remains on the books of several agencies and is in touch with several schools in Essex, offers of work are increasingly rare.

“I’ve only had one day this year,” he says. “But I’d still like to teach, and I’m still available. I tend to get up early in the morning, just in case I get a last-minute call. It doesn’t happen very often now, but I’m always an optimist.”