xxxix] HAMPDEN AND THE FLAT EARTH 365 



In Scientific Opinion of January 12, 1870, Mr. John 

 Hampden (a relative of Bishop Hampden) challenged 

 scientific men to prove the convexity of the surface of any 

 inland water, offering to stake £500 on the result. It con- 

 tained the following words : ■ He will acknowledge that he 

 has forfeited his deposit if his opponent can exhibit, to the 

 satisfaction of any intelligent referee, a convex railway, river, 

 canal, or lake." Before accepting this challenge I showed it 

 to Sir Charles Lyell, and asked him whether he thought I 

 might accept it. He replied, " Certainly. It may stop these 

 foolish people to have it plainly shown them." I therefore 

 wrote accepting the offer, proposing Bala lake, in North 

 Wales, for the experiment, and Mr. J. H. Walsh, editor of 

 the Field, or any other suitable person, as referee. Mr. 

 Hampden proposed the Old Bedford canal in Norfolk, which, 

 near Downham Market, has a stretch of six miles quite straight 

 between two bridges. He also proposed a Mr. William 

 Carpenter (a journeyman printer, who had written a book 

 upholding the " flat earth " theory) as his referee ; and as Mr. 

 Walsh could not stay away from London more than one day, 

 which was foggy, I chose Mr. Coulcher, a surgeon and amateur 

 astronomer, of Downham Market, to act on my behalf, Mr. 

 Walsh being the umpire and referee. 



The experiment finally agreed upon was as follows : The 

 iron parapet of Welney bridge was thirteen feet three inches 

 above the water of the canal. The Old Bedford bridge, about 

 six miles off, was of brick and somewhat higher. On this 

 bridge I fixed a large sheet of white calico, six feet long and 

 three feet deep, with a thick black band along the centre, the 

 lower edge of which was the same height from the water as the 

 parapet of Welney bridge ; so that the centre of it would be 

 as high as the line of sight of the large six-inch telescope 

 I had brought with me. At the centre point, about three 

 miles from each bridge, I fixed up a long pole with two red 

 discs on it, the upper one having its centre the same height 

 above the water as the centre of the black band and of the 

 telescope, while the second disc was four feet lower down. It 

 is evident that if the surface of the water is a perfectly straight 



