In an article in the Scientific American a short time ago, we said, in answer to some hasty remarks made by the " Niagara Mail," when ever it is shown that a British clipper ship has beaten any American one in a fair race—mdash;, day by day—mdash;we will give the winning ship full credit for the same, and not feel the least chop fallen." We also called upon those who boasted of the superiority of the British clip pers, to show their courage and confidence by taking up the Boston challenge. The " London Expositor " has made some comments upon our remarks, which are very temperate, although it is mistaken in suppo sing there is any acidity in our dispute with the "Niagara Mail." The " Expositor " asserts that the Ameri can clipper ships were beaten last year by the Aberdeen built clippers. If so, we give them full credit for having done so well, but the ac counts received by us are as follows :—mdash;" Aber deen ship Chrysolite, 106 days from Canton to Liverpool; American ship Challenge, 105 days from Canton to Deal: British ship Stornaway, 109 days from Canton to Deal; American ship Surprise, 106 days from Can ton to Deal. From Shanghai to Deal, Ameri can ship Nightingale, 110 days; British ship Challenge, from same place to Liverpool, 113 days. It appears to us that the races are in favor of the American ships. The Chrysolite appears to be as fast a clipper as any of ours, and the Aberdonians deserve great credit for the fine ships which they build; they are manfully upholding any credit that England has for fast sailing ships. The " Expositor " alludes to the recent voyages of the Marco Polo, a clipper ship built in New Brunswick, N. A., and says, " it ran from Liverpool to Australia in 60 days; we do not know if any ship built in an American port has ever equal led her speed ; in her run home she repeated ly made 300 miles in 24 hours." The Marco Polo has done well, we wish not to ruffle a feather of the plume which her builders de serve ; at the same time let us observe she is an American built ship, not a Yankee one td be sure, but a provincial one. Our next door neighbors cannot live so near us and not catch the true spirit. The clipper ship " Fly ing Cloud," built in Boston, by D. Mackay, however, has run 336 miles in 24 hours, thus beating the Marco Polo. We do not wish to be speaking of these things like jockeys about the conflicts on the "turf," we believe that the spirit of emulation in building fast ships, is a noble one ; it tends to advance one of the no blest—mdash;if not the noblest—mdash;of architectural arts, therefore we say the prudence of the Bri tish merchants spoken of by the " Expositor " in respect to betting, although we commend them for their principles, shows that they do not feel the keen spirit of national rivalry in this contest, or else they have no confidence in their own ships. Thesemust be thecauses for not accepting the Boston challenge, for Lon don merchants are not more moral than our Bos ton friends. We must take this occasion to say that in principle we are opposed to all betting—mdash;these conflicts for an honorable su periority should all be for love, as a son of the Emerald Isle would say. We will still con sider the American clipper ships as the vic tors on the ocean race course ; and must do so until we have particular evidence to the con trary.