Coronation Periscopes

"Where're you going with them, Sonny?"
The driver with trousers up to his armpits asked.
"On the coach. I came with my school to see the Coronation Parade."
"That may be so, but what are all these? You can't fill up my coach with them."
"They're periscopes people used then to see over the heads of the crowds. Then they dropped them after the parade went by."
A policeman came over, winked at the driver and said,
"What's going on here then?"
It's funny how grown ups think that kids can't see them wink at one another.
"Periscopes, people threw them away. So I picked them up."
The policeman smiled,
"All periscopes belong to the Queen, you can't just go walking off with them. Unless you have a reason, lad?"
"They're for my Dad. We are going to use them to look at Mars."
"Bit of an astrologer is he, your Dad?" Said the coach driver with another wink.
I said, "No. He works in a shirt factory."
"Reckon you've enough periscopes to stretch to Mars, Lad?"
"I've got thirty two"
"Let's see then," said the policeman, "you've got thirty two periscopes at, eighteen inches each, so how long will that be, when you join them all together?"
Each periscope was a long cardboard box with a mirror at each end. My arms were aching holding them now. Our teacher arrived with a group of kids from school. The policeman explained the problem to him, with a wink. The coach driver thought this was so funny, he nearly choked himself on his fag, laughing. Then the kid's all joined in.
I tried to work it out. Thirty-two times eighteen, I couldn't do that. Then I remembered my Dad saying that sometimes it helped to swap sums round. So, eighteen times thirty-two, couldn't do that either, hang on, eighteen inches was the same as one and a half feet. So one and a half thirty-twos, that was thirty-two add half of thirty-two that makes ...
The coach driver was passing fags round to the policeman and the teacher.
Thirty-two add sixteen is....
"Forty eight," I shouted.
"What's that lad?" The policeman said, waving out his match and blowing a cloud of smoke in the air.
"It's forty-eight feet, all the periscopes together."
"Is that correct Sir?" The policeman winked at the teacher.
"Sounds right to me."
"Then you had better get them on the coach, lad." said the policeman.
The driver pushed his belly out and said through his fag.
"I suppose I can bend the Rules, this once."
I sat down and the teacher sat next to me.
"Well done Turvey. What do you want all the periscopes for?"
"My Dad says that if we had a powerful periscope we could see the canals on Mars."
"Sure your Dad didn't say 'telescope', Turvey?"
"No. He definitely said 'periscope' Sir."
I hid behind the pile of periscopes, felt my face go red and remembered; it was 'telescopes'.