With England, our explanations will be much more delicate. They are the older country, the mother country, more advanced in the arts and sciences, possessing more wealth and leisure for their improvement, and animated by a pride more than laudable.[1] It is their measures, too, which we undertake to ascertain and communicate to themselves. The subject should therefore be opened to them with infinite tenderness and respect, and in some way which might give them due place in its agency. The parallel of 45° being within our latitude and not within theirs, the actual experiments under that would be of course assignable to us. But as a corrective, I would propose that they should ascertain the length of the pendulum vibrating seconds in the city of London, or at the observatory of Greenwich, while we should do the same in an equidistant parallel to the south of 45°, suppose in 38° 29´. We might ask of them, too, as they are in possession of the standards of Guildhall, of which we can have but an unauthentic account, to make the actual application of those standards to the pendulum when ascertained. The operation we should undertake under the 45th parallel, (about Passamaquoddy,) would give us a happy occasion, too, of engaging our sister society of Boston in our views, by referring to them the execution of that part of the work. For that of 38° 29´ we should be at a loss. It crosses the tide waters of the Potomac, about Dumfries, and I do not know what our resources there would be unless we borrow them from Washington, where there are competent persons. Although I have not mentioned Philadelphia in these operations, I by no means propose to relinquish the benefit of observations to be made there. Her science and perfection in the arts would be a valuable corrective to the less perfect state of them in the other places of observation. Indeed, it is to be wished that Philadelphia could be made the point of observation south of 45°, and that the Royal Society would undertake the counterpoint on the north, which would be somewhere between the Lizard and Falmouth. The actual pendulums from both of our points of observation, and not merely the measures of them, should be delivered to the Philosophical Society, to be measured under their eye and direction.