While the trays and chemicals were being arranged, Caleb explained to the pastor that photographs were first taken on glass plates, chemically treated, and that the picture proper was made by light passing through a plate to the surface of sensitized paper. When the red lamp was lighted, Caleb continued:-- "Now, when Mis' Somerton lays a plate in that tray, you'll see it's as blank as a sheet o' paper, or as the faces o' some o' the ungodly that you've been preachin' at an' laborin' with, year in and year out. You can't see nothin' on it, no matter if you use a hundred-power magnifyin' glass. But the pictur' 's there all the same; it was took weeks ago; might ha' been months or years, but it's there, an' yet the thing goes on lookin' blank till the developer is poured on it--just like Mis' Somerton's doin' now. Now keep your eye on it. It don't seem to mind, at first--goes on lookin' as blank as the faces o' case-hardened sinners at a revival meetin'. But bimeby--pretty soon--" "See those spots!" exclaimed the minister. "Eh? Why, to be sure. Well, a photograph plate is a good deal like measles an' religion--it first breaks out in spots. But keep on lookin'--see it come!" "Wonderful! Wonderful!" exclaimed the minister. "Seemed miraculous to me, first time I see it," said Caleb. "I'd have been skeered if Mis' Somerton hadn't said 'twas all right, for no magic stories I ever read held a candle to it. But keep on lookin'. See one thing comin' after another, an' all of 'em comin' plainer an' stronger ev'ry minute? Could you 'a' b'lieved it, if you hadn't seen it with your own eyes? An' even now you've seen it, don't it 'pear 'bout as mysterious as the ways o' Providence? I've read all Mis' Somerton's book tells about it, an' a lot more in the cyclopeedy, but it ain't no less wonderful than it was." "Absolutely marvellous!" replied the minister.