1849.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



247 



i; 



The settliii": of the vast bottom of mud and earth took two years; 

 and the cradle of masonry which surrounds it, capabl" of receiving 

 the largest merchant ships, is 170 feet long, 40 feet wide, and 30 

 feet deep. The other works throughout the canal are on a similar 

 scale. At the entrance of the lakes, owing to tlie sponginess of 

 the ground, great difficulties were surmounted by the perseverance 

 of the engineer. The dredging necessary for excavation of such 

 an extent was constructed with immense ingenuity. Neptune's 

 Staircase, which we have already mentioned as connecting eight 

 locks in succession, contains 400 yards of solid masonry. A con- 

 struction of the kind had never been attempted before. 



On the whole, few works show more vividly the untiring in- 

 genuity and perseverance of the country than the Caledonian 

 Canal. 



No. III. — Lighthouses. 



Before the invention of the mariner's compass, beacons and 

 coast signals were indispensable for the safety of the mariner. 

 The vessels whose safe voyaging depended upon their never losing 

 sight of land, trusted to the natural and artificial signs which en- 

 abled the pilot to determine his position; and this object was ac- 

 complished in many instances by beacon lights, which served for 

 guides during the darkness of night. Around the shores of the 

 Mediterranean we have reason to believe that these lights were 

 thickly studded — the Colossus of Rhodes and the Pharos of Alex- 

 andria being the most celebrated. Both of these beacons are sup- 

 posed to have been erected about 300 years before the Christian 

 era, and to have endured until long after its commencement. 

 Next to these in point of time was a light-tower near Corunna, on 

 the Spanish coast, built, it is said, to aid the Irish navigators in 

 their voyages to Spain — this, at least, is the supposition of Mr. 

 Moore, in his 'History of Ireland' — and which Humboldt states to 

 be evidently an erection of the Roman period. The light in all 

 these beacons was derived solely from the flame of wood or pitch 

 burnt in open braziers, and visible comparatively for small dis- 

 tances. 



Turning to the lighthouses of modern days, we find that the 

 light-tower of Corduan, in the Bay of Biscay, is alike the first in 

 point of time, the chief in height and range, and the example for 

 all the improvements that have been successively made in the pro- 

 duction and transmission of the warning rays of light to perplexed 

 mariners. This tower was begun by Louis de Foix, in the reign of 

 Henry II. of France, a.d. 158i, and finished in 1610, under 

 Henry IV. It is situated at the mouth of the Garonne, about two 

 leagues from Bordeaux, and serves as a direction to all the coast 

 navigation of the Bay of Biscay, as well as to the large influx of 

 shipping attracted towards the embouchure of the celebrated Lan- 

 guedoc Canal, which leads into the Mediterranean. The Tour de 

 Corduan is 157 feet in height, and its light may be seen in a di- 

 rect line for 25 miles in clear weather. Even on the Isle of Bone, 

 38 miles distant, a spectator, looking from some elevated point, 

 may detect the blaze in the horizon; but the curvature of the 

 ocean hides the light from the seaman on deck. Its light is inter- 

 mitting, changing, at half-minute intervals, from white to red. 

 Even the red rays, whose penetrating powers are far inferior to 

 the white, are visible as far as 12 or 14 miles, except in hazy wea- 

 ther. From its erection down to 1780 the light of this tower was 

 derived from the flame of wood. In that year M. Senoir substi- 

 tuted oil-lamps, with metal reflectors; and in 1822 M. Fresnel ex- 

 tended the range of illumination to the extraordinary distances 

 we have mentioned above, by the addition of dioptric lenses, acting 

 upon lamps of an improved and more powerful construction. The 

 use of this and similar beacons upon that coast has been enormous. 

 In the era of its first erection one of the Breton counts, who, as 

 lord of the soil, possessed rights of trover and wreckage along the 

 coast, is said to have boasted to a jeweller that a single black rock 

 which stood in the tideway was more valuable to him than the best 

 diamond in his caskets. 



In England, the earliest lights and beacons along the coast were 

 erected by individuals, to whom royal patents were granted, au- 

 thorising them to collect certain tolls from the passing vessels to 

 defray the cost of building and maintenance, 'f he right of con- 

 structing those sea signals, however, rested solely with the crown; 

 and, in fact, the far larger number were used only in times of war- 

 like expedition, and for cei'tain special purposes. The earliest 

 lighthouse which still remains in existence was that of Lowestoft, 

 built in IfiOO. Another at Hurstbarton Point, on the east coast, 

 was erected in 1665; and the light on the Scilly Isles dates its es- 

 tablishment from 1680. Besides these there were two light-towers 

 erected during this period at Dungeness and Orfurdness, under 



patents gra, _ '„_, James I. to Sir R. Howard and SirVI'^. Erskine. 

 These establishmei^ts remained private property, paying only a 

 small quit-rent to tiie crown, until very recently, whe.i the Trinity 

 Board, under the act of 1836, purchased them both at a high price 

 from their owners, Mr. Coke and Lord Braybrooke. 



The earliest of the above dates (1609) saw the final establish- 

 ment of that board under whose control all the English lighthouses, 

 and almost all the autliority over English commerce and naviga- 

 tion, was ultimately to pass — namely, the Brotherhood of the 

 Trinity-house. This institution first commenced in the time of 

 Henry VII., as a private confraternity of seamen and shippers. 

 In the sixth year of his successor, Henry VIII., the brotlierhood 

 received their first charter as a recognised "Guild," under the title 

 of the "Brotherhood of the Trinity-house of Deptford le Strand 

 and St. Clement." The charter commences with the curious decla- 

 ration, that "On account of the sincere and entire love, and like- 

 wise devotion, which we bear and have towards the most glorious 

 and undividable Trinity, and also St. Clement the Confessor," his 

 Majesty gives and grants licence for the establishment of a guild, 

 or perpetual fraternity, to certain individuals and their associates, 

 "as well men as women." Early in Elizabeth's reign this charter 

 was confirmed, and again in the 36th year of that sovereign, when, 

 for the first time, those powers were granted which have subse- 

 quently led to the authority of the Trinity Board over all light- 

 houses. In that year the Lord High Admiral of England, Charles 

 Howard of Effingliam, formally relinquished all claims on his part 

 and on the part of the crown in the rights, privileges, and emolu- 

 ments for "buoyage, ballastage, and beaconage," which were 

 thenceforth assigned to the Trinity Brotherhood. James II., ia 

 confirming this charter extended the powers of the fraternity, and 

 organised the board pretty much as it still exists. His first patent 

 appoints "Our trusty and well-beloved Samuel Pepys, Esq., secre- 

 tary of our Admiralty of England, to be the fii-st and present 

 Master of the said Guild, Fraternity, or Brotherhood." The char- 

 ter was again enrolled and confirmed by George II., and in the 

 6th and 7th session of William IV., the Trinity-house received 

 enlarged powers, under which the whole number of liglithouses on 

 the English coasts, many of which had up to tliat time remained 

 private property, under grants or leases, were re-purchased, and 

 amalgamated under a uniform administration. The only exemp- 

 tions to the rule of the Trinity Board are in the instances of 

 certain harbour lights, which still continue in the control of local 

 trustees. 



The dates of the several patents granted to the Trinity-house 

 begin with 1680, when Charles II. authorised the erection of the 

 Scilly Light. Two other patents were issued by that monarch, for 

 the light beacons of Spurm and Tynemouth Castle. Anne granted 

 one patent to the Trinity-house for Milford Haven; George I. 

 granted four; George II., seven; George III., fifteen; George IV., 

 seven; and William IV., five. 



The year 1656 saw the foundation first laid for that celebrated 

 structure the Eddystone Lighthouse. Mr. Winstanley was the 

 architect, and the tower stood 60 feet high in a sea whose waves, 

 during heavy storms, dash to an altitude of nearly 100 feet above 

 the lantern. The light was first exhibited in 1698, and burnt 

 steadily for five years, when the whole edifice was swept away by 

 a furious gale in November, 1703, while Mr. Winstanley was him- 

 self within it. This lighthouse was formed of courses of stone, 

 bound together with timber, and its destruction is attributed to 

 the comparative lightness of its materials and the slight founda- 

 tion prepared for it on the rock. 



A tradesman on Ludgate-hill. Mr. Rudyerd, then undertook the 

 construction of a tower, wholly of wood. The form was that of 

 a conical cask, 70 feet high, with its lower ranges stiff'ened and 

 strengthened with courses of masonry. But the chief improve- 

 ment in this tower was in the contrivance of its foundations. The 

 irregular and shelving surface of the rock was levelled into a 

 range of broad steps. Into these steps a number of holes were 

 drilled, in sets of three each, diverging slightly from above down- 

 wards; when tlie three being broken into one, left a cavity of a 

 conical form, widest at its lower end. A compound wedge of iron 

 being driven tight into this cavity, clamped together, and the in- 

 terstices filled with melted lead, formed an immovable basis 

 whereto the lower piles of timber or blocks of stone might be se- 

 cured. This contrivance, introduced by Mr. Rudyerd in the Ed- 

 dystone, has since been extensively employed in lighthouse and 

 submarine works. The wooden tower bore the brunt of the wea- 

 ther from 1708 until 1755, when it unfortunately caught fire, and, 

 after burning for several days, was totally consumed. Two years 

 later Mr. Smeaton was engaged in founding the present edifice. 

 On the 16th October, 1759, the lights were first shown, and hav« 



