The leading reflection to which this occasion seems to invite us, respects the great changes which have happened in the fifty years since the battle of Bunker Hill was fought. And it peculiarly marks the character of the present age, that, in looking at these changes, and in estimating their effect on our condition, we are obliged to consider, not what has been done in our own country only, but in others also. In these interesting times, while nations are making separate and individual advances in improvement, they make, too, a common progress; like vessels on a common tide, propelled by the gales at different rates, according to their several structure and management, but all moved forward by one mighty current, strong enough to bear onward whatever does not sink beneath it. A chief distinction of the present day is a community of opinions and knowledge amongst men in different nations, existing in a degree heretofore unknown. Knowledge has, in our time, triumphed, and is triumphing, over distance, over difference of languages, over diversity of habits, over prejudice, and over bigotry. The civilized and Christian world is fast learning the great lesson, that difference of nation does not imply necessary hostility, and that all contact need not be war. The whole world is becoming a common field for intellect to act in. Energy of mind, genius, power, wheresoever it exists, may speak out in any tongue, and the _world_ will hear it. A great chord of sentiment and feeling runs through two continents, and vibrates over both. Every breeze wafts intelligence from country to country; every wave rolls it; all give it forth, and all in turn receive it. There is a vast commerce of ideas; there are marts and exchanges for intellectual discoveries, and a wonderful fellowship of those individual intelligences which make up the mind and opinion of the age. Mind is the great lever of all things; human thought is the process by which human ends are ultimately answered; and the diffusion of knowledge, so astonishing in the last half-century, has rendered innumerable minds, variously gifted by nature, competent to be competitors or fellow-workers on the theatre of intellectual operation.