The challenge of the " American Navigation Club," offering a bet of 10,000 as a prize to the winning vessel, a Yankee ship against a British one, of 1,200 tons burden, to run from London to China and back, has not yet been accepted. It was to stand open for 30 days. The club, unwilling that England should so far forget her old chivalry, has extended the period for accepting the challenge, and will augment the stakes to 20,000, and give the British ship 14 days of a start. Is there not public spirit in all old England to accept this challenge? As this race does not involve high pressure steam, we hope to see the challenge taken up, or an offer made to race for love to test the relative speed of American and English built ships. A correspondent of the London Mechanics' Magazine criticised Mr. Griffith's work on ship-building, and insinuated that the English shipwrights were better acquainted with the science than the American ones. Here is an opportunity for him to prove it. He should exert himself to find some one te accept the challenge, when he does so he will find the stakes by calling on Mr. Peabody, in London