“‘By my operations I make the distance to be 48,362 feet, differing by only seven feet in upwards of nine miles. The distance of Wednesbury spire from the station at Bar beacon is, according to Colonel Mudge, 25,140 feet. This, reduced to the distance from the flagstaff, is 25,098 feet. I have found the same line to measure 25,102 feet, differing by only four feet in nearly five miles.[43] * * * * * “‘Besides measuring these distances, I reduced the latitude and longitude of St. Philip’s church, and of the station on this house [my father’s], from the latitude and longitude of Bar beacon as given by Colonel Mudge.’[44] “One other line measured in the course of my operations (I think it was the one from the station on Bar beacon to that on Clent Hill near Hagley) was of yet greater length than those mentioned above, being no less than fourteen miles. Indeed, the triangles became so large that I had to make allowance for spherical excess, the rotundity of the earth becoming otherwise a source of error. “Whenever it was practicable I measured all three angles of each triangle; and, after allowance for the spherical excess, there was no instance, I believe, in which the sum of the three angles differed from 180° by so much as half a minute. “Those possessed of such instruments as are used at the present day will perhaps smile at the self-satisfaction with which I regarded this approximate accuracy; but they must remember that I had only a common theodolite, such as was in use fifty years ago. “It may be mentioned here that, on account of the length of the lines, communication between our stations was a matter of some difficulty and much interest. When two divisions of the surveying class had to set out in different directions for places many miles apart, for the purpose of acting in concert with each other, of course a certain amount of forethought and injunction before starting, and sharp watchfulness on the spot, were indispensable: spare flags were carried for telegraphic purposes, and telescopes for observation of the signals previously agreed upon. I need not say that each signal at one station was eagerly welcomed at the other, and that its repetition, given by way of acknowledgment at the latter, was no less warmly hailed at the former.