It is far from necessary to my present object, to state all that has been written and said respecting these pendulum experiments: I shall confine myself merely to two points; one, the transit observations, I shall allude to, because I may perhaps show the kind of feeling that exists respecting them, and possibly enable Captain Sabine to explain them. The other point, the error in the estimation of the division of the level, I shall discuss, because it is an admitted fact. Some opinion may be formed of transit observations, by taking the difference of times of the passage of any star between the several wires; supposing the distances of those wires equal, the intervals of time occupied by the star in passing from one to the other, ought to be precisely the same. As those times of passing from one wire to another are usually given to seconds and tenths of seconds, it rarely happens that the accordance is perfect. The transit instrument used by Captain Sabine was thirty inches in length, and the wires are stated to be equi-distant. Out of about 370 transits, there are eighty-seven, or nearly one-fourth, which have the intervals between all the wires agreeing to the same, the tenth of a second. At Sierra Leone, nineteen out of seventy-two have the same accordance; and of the moon culminating stars, p. 409, twelve out of twenty-four are equally exact. With larger instruments, and in great observatories, this is not always the case. Captain Kater has given, in the Philosophical Transactions, 1819, p. 427, a series of transits, with a three and a half foot transit, in which about one-eleventh part of them only have this degree of accuracy; and it should be observed that not merely the instrument, but the stars selected, have, in this instance, an advantage over Captain Sabine's. The transit of M. Bessel is five feet in length, made by Frauenhofer, and the magnifying power employed is 182; yet, out of some observations of his in January, 1826, only one-eleventh have this degree of accordance. In thirty-three of the Greenwich observations of January, 1828, fifteen have this agreement, or five-elevenths; but this is with a ten-feet transit. Now in none of these instances do the times agree within a tenth of a second between all the wires; but I have accounted those as agreeing in all the wires in which there is not more than four-tenths of a second between the greatest and least.