Shall I go sir ?" "Perhaps you'd better," said Thorndyke.

"It may not be Mr.Britton, and I don't want to be caught and delayed just now." However, it was Mr.Britton; a breezy alert-looking middle-aged man, who came in escorted by Polton and shook our hands cordially, having been previously warned of my presence.

He carried a small but solid hand-bag, to which he clung tenaciously up to the very moment when its contents were required for use.
"So that is the camera," said he, running an inquisitive eye over the instrument.

"Very fine one, too; I am a bit of a photographer myself.
What is that graduation on the side-bar ?" "Those are the scales," replied Thorndyke, "that shows the degree of magnification or reduction.

The pointer is fixed to the easel and travels with it, of course, showing the exact size of the photograph.
When the pointer is opposite o the photograph will be identical in size with the object photographed; when it points to, say, x 6, the photograph will be six times as long as the object, or magnified thirty-six times superficially, whereas if the pointer is at / 6, the photograph will be a sixth of the length of the object, or one thirty-sixth superficial." "Why are there two scales ?" Mr.Britton asked.
"There is a separate scale for each of the two lenses that we principally use.