I write with the roar of the Niagara Falls in my ears. We have come here for a few days' rest, and that I may get rid of a bad cold in the presence of this most stupendous of all the works of nature. It is hopeless to attempt to describe what so many have been describing; but the effect, I think, surpassed my expectations. The day was waning when we arrived, and a turn of the road brought us all at once in face of the mass of water forming the American Fall, and throwing itself over the brink into the abyss. Then another turn and we were in presence of the British Fall, over which a still greater volume of water seems to be precipitated, and in the midst of which a white cloud of spray was soaring till it rose far above the summit of the ledge and was dispersed by the wind. This day we walked as far as the Table Rock which overhangs one side of the Horse-shoe Fall, and made a closer acquaintance with it; but intimacy serves rather to heighten than to diminish the effect produced on the eye and the ear by this wonderful phenomenon. The following to Lord Grey is of the same date:-- Our tour has been thus far prosperous in all respects except weather, which has been by no means favourable. I attended a great Agricultural Meeting at Hamilton last week, and had an opportunity of expressing my sentiments at a dinner, in the presence of six or seven hundred substantial Upper Canada yeomen--a body of men not easily to be matched. It is indeed a glorious country, and after passing, as I have done within the last fortnight, from the citadel of Quebec to the Falls of Niagara, rubbing shoulders the while with its free and perfectly independent inhabitants, one begins to doubt whether it be possible to acquire a sufficient knowledge of man or nature, or to obtain an insight into the future of nations, without visiting America. A portion of the speech to which he refers in the foregoing letter may be here given, as a specimen of his occasional addresses, which were very numerous; for though the main purposes of his life were such as 'wrote themselves in action not in word,' he regarded his faculty of ready and effective speaking as an engine which it was his duty to use, whenever occasion arose, for the purpose of conciliating or instructing. In proposing the toast of 'Prosperity to the Agricultural Association of Upper Canada,' he said:-- [Sidenote: Speech at an agricultural meeting.]