Let us look at “above the level of the sea” in another light. The staircase height of each of the houses we have referred to is about sixty feet, a fatiguing ascension even for the lightest of us. The summit of the Mont Cenis Pass is exactly 111 times 60. The top of St. Paul’s Cathedral is 404 feet from the ground at St. Paul’s Churchyard. The summit of the Mont Cenis Pass is sixteen and a half times higher.
Elevation by steps is only available for man, and for man’s ever faithful, as well as for man’s doubtfully faithful, companions, the dog and the cat. They therefore are able to ascend and descend a staircase gradient of 1 in 2; not so all other useful and domestic animals—the horse, the mule, the sheep, and the cow can only go along a continuous roadway; the mountain goat can skip occasionally from rock to rock, but its normal step is that of the other animals we have just enumerated. Were the steps of a staircase covered over, say with boards, and the ascent made uniform, man could not ascend or descend a gradient of 1 in 2, 1 in 3, 1 in 4, and scarcely 1 in 5. He could not, in fact, ascend or descend the last-named gradient without having something beside him to hold on by. But the muscles of man’s legs, and the organisation of his feet, enable him, by one of the innumerable and beautiful arrangements of the all-provident Creator, to ascend elevations by steps with complete facility, and at any moment. The steepest gradient that a horse can ascend or descend for any distance with a load is 1 in 10; occasionally there are short slopes in roads, especially old ones, of 1 in 6 or 7, but they overtax muscular strength in which ever direction an animal is going. It is a good mountain road the gradient of which does not exceed 1 in 15, or 352 feet in a mile, excellent, if it be anything like 1 in 20, or 264 feet in a mile. A strong, well-fed English horse with a moderate load behind him, could trot up this latter gradient for a short distance, and then he would fall into a walking pace, but he would draw a heavier load and with less distress to himself if he be started at a walk and be never pressed out of it.
Being anxious to show by an illustration, which would be familiar to most persons, who are either resident in, or have visited London, what is a gradient, we applied for information to Mr. Wm. Haywood, the engineer of the Corporation of London, under whose direction the Holborn Viaduct and Embankment are now in course of construction. He has kindly and courteously furnished a diagram—a copy of which is annexed at the end of the volume, showing in minute detail the variations of gradient, from Staples Inn to opposite the Old Bailey and Giltspur Street. The total length from point to point is 2,202 feet, a little more than two-fifths of a mile. The steepest gradient is 1 in 15 (352 feet in the mile) for 86 feet, the next 1 in 18 (293 feet in the mile) for 257 feet, and 1 in 19 (278 feet in the mile) for 113 feet. These gradients are all on Holborn Hill, between Hatton Garden and Shoe Lane. The steepest on Snow Hill is 1 in 21 (251 feet in the mile) for 87 feet, and 1 in 24 (220 feet in the mile) for 312 feet. All these gradients will, however, in a year or so, be matters of history, for it is hoped that the Holborn Viaduct will be opened for traffic at the beginning of 1869.[115]
It is, however, a misnomer to call it a viaduct. It is true that, by means of a massive construction, the opposite sides of a valley—at their summits more than two-fifths of a mile apart—are connected together on the level. But, in reality, the viaduct is a great metropolitan work, worthy of the Corporation of the City of London, which, although well abused by persons who do not understand its operations, is never-ceasing, to the extent of its means, in carrying out improvements within its limits. A list of the works and changes effected by the Corporation in the last thirty years would show that it has expended millions in altering the face of the City,[116] and in increasing facilities for traffic, especially at points of aggregation. The manner in which the new street that is to run from the Mansion House to Blackfriars Bridge, within City boundaries, is advancing, contrasts markedly with what is doing beyond them. According to present appearances, the City will have completed its work and opened its portion of the street for traffic about the time that the Metropolitan Board of Works will have made a fair start upon what it has to accomplish.
The next great work that the Corporation has to take in hand is the widening of the Poultry, infinitely more important, and more absolutely required, in the opinion of all people who frequent the City, than the widening of Newgate Street, upon which the Corporation is now engaged. The expense, of course, will be enormous, but it must be met—somehow: land to be paid for by the square inch; splendid constructions to come down; historic Bucklersbury to disappear; even the Mansion House will stop the way, and His Lordship will have to find residence either at the rear of Guildhall, as was suggested some short time ago, or elsewhere. Metropolitan fellow residents, metropolitan suburbanists, and inhabitants who dwell to the extent of six miles outside the Post-Master General’s twelve mile postal circle, you may all rest assured that the granite pillars you see at the eighteen mile distance post from London, on railway and roadway, on river bank and canal tow-path—the columns of Luxor of the Corporation—with inscriptions on them destined, in remote future times, to represent the hieroglyphics of ancient Anglia—will remain and be found among the few signs then extant, of the by-gone civilisation which the prophesied New Zealander is to make his musings upon. Of the London coal tax as of the river:—
“Rusticus expectat dum defluit amnis; at ille
Labitur et labetur in omne volubilis ævum.”[117]
The tax exists ex necessitate rerum, and must continue notwithstanding fervescence frequent—always at boiling point—in Parochial Parliaments, with echoes occasional in that of St. Stephens.