1839.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



109 



of 20 feet of water at liigh water of an ordinary neap-tide. Tlie operations 

 wliich were necessary in making tliis lock were entirely dissimilar, but not 

 much less difficult than those at Claclmacharry, and are worthy of 

 attention. 



•' The connection with the tideway being to the westward of the general 

 line of the valley, and at the rectangidar turn of Locli-Eil towards Fort - 

 William, a well-sheltered roadstead and good anchorage are here obtained. 

 Loch-Eil and the Linnhc-Loch are inlets of the west sea, and the latter 

 joins the usual channel of navigation south of the Sound of Mull. 



" The navigation by tlie Caledonian Canal between the two seas was 

 opened at the latter end of 1823 ; the eastern district had previously been 

 navigated three years." 



From the above description of the works in the neighbourliood of 

 Torvaine the profes.sional reader would be led astray, Ibv no notice is 

 taken of the difficulties wliich impeded the progress of the «orks, 

 and wliich still cause them to remain in a defective state. 



To understand this, it must be observed that Torvaine is the name 

 of a very high hill of sand and gravel, at the base of which flows 

 the River Ness, and it was necessary to widen the bed of the river 

 on the south side, which, at the same time, produced earth for sepa- 

 rating the river and canal, as staled above, by removing the opposite 

 bank ; for in fact, there was no opposite bank to remove, t!ie land on 

 that side being very low and flat ; and although the widening was 

 rather considerable, the earth so obtained formed but a small portion 

 of what was necessary to separate, by a proper embankment, the 

 river and the canal, the hill of Torvaine, although at least 150 feet 

 above the river, had to be cut into to a considerable extent, before a 

 sufficient quantity of stuff coidd be procured and the canal was 

 partly constructed on the hill, and partly in the river. The annexed 

 sketch will better describe the features of the canal at this particular 

 place, and show the peculiar nature of the position. 



A— The Ness River. 



B — The Caledonian Canal, partly cut out of the foot of the hill, 50 



feet wide at the bottom, and 120 feet at the top, and 20 feet deep. 

 C — Embankment formed from the cutting opposite, with a slope of 1| 



to I , and 20 feet wide on the top, which divides the canal and the 



river Ness. 

 D — The part of Torvaine Hill cut away, with a slope of 2i to 1, and 



benches 10 feet wide- 



The course of the canal from the Muirtown Locks, on towards 

 Torvaine, passes through a stratum of clay, but as it more nearly 

 approaches Tomnahuric and Torvaine, the stratification ! becomes 

 loose and porous. At Torvaine, in particular, the whole hill is com- 

 posed of sand and gravel, which continues through the Muir of 

 Dunanclu'oy, and on to Dochgaveh. The engineers, notwithstanding 

 the knowledge of these materials fonning the banks of the 

 canal, neglected taking any precaution to line the canal with 

 puddle, but entirely depended on the great supply of water which 

 they had in the Loch and River Ness, which run close to the canal 

 through nearly the whole district. Tliese, they trusted, would 

 supply the loss of any water by filtration ; and they also calculated 

 that, by means of this, the deposit of the river would ultimately have 

 filled up the interstices of the gravel, and that, thereby, the canal 

 would be rendered water-tight. With this impression, no side- 

 lining or bottcm puddle was provided, and the consequence was, 

 that they could never keep the canal full, but the water filtered out 

 before it reached Tomnahuric. This circumstance occasioned much 

 surprise and dijappoiritmcnt at that time, and a dam was placed 

 across the canal, to retain a dej th of about five feet of water through 

 the Moir of Dunanchroy, so as to try the effects of filtering. Many 

 thou^and tons of loamy silt were brought down and hove into the 

 bottom of the canal, but to no purpose; for, as fast as it was thrown 

 in, it was carried through the sides and the bottom into the river ; 

 and instead of the silt filling up the interstices, every part of the 

 canal when the water was let in, became more and more porous ; for 



the water not only carried away the stuff thrown into the canal, but 

 it also caiTJed away all the sand and smaller pebbles, making the 

 gravel still more porous, so that in a very short time the bottom and 

 sides of the canal became as open as if it had been made through a 

 mountain of macadamized stone. The contractors were employed 

 for many days near Dunanchroy, trying to prevent the leakage, but 

 without the least practical effect. 



There can be no doubt that the want of a puddle lining in this 

 part of the canal was attended with disappointment, great expense, 

 and to a certain extent a failure of what the canal proposed to be, 

 and what it ought to have been conducted on a different plan. Instead 

 of using the porous materials of Torvaine Hill for the embankment, 

 the clay which was found between Torvaine and the Muirtown 

 Locks should have been employed, instead of which it was wheeled 

 into spoil, and thus thrown to waste. The canal ought also to have 

 been cut much deeper and wider, not only to receive the necessary 

 puddle of clay, but also for a sufficient protection of gravel facing to 

 keep it firm. All this could have been done at half the expense, or 

 perhaps one-third, of that afterwards incurred ; but the most unfortu- 

 nate part remains yet to be told. It is a fact, that after having proved 

 the ineffectual and superficial manner in which the canal had been 

 constructed, and having determined to deepen and \viden it to the 

 necessary size for receiving a proper thickness of puddle to resist the 

 pressure of water, by some unaccountiible en'or the canal was never 

 made deep nor wide enough for the purpose, and up to this day the 

 canal at that part has not strength of side and bottom lining to 

 carry more than 12 feet water, instead of 20. We ask the editor, is 

 not this the true cause of the failure of the canal, instead of the ridi- 

 culous statement set forth in the work before us at page 66 ? The 

 facts we have stated are quite sufficient to prevent large vessels from 

 navigating this canal, and until the line is made perfect there, it is 

 quite uieless to have 20 feet of water in any other part. We recom- 

 mend strongly that an inquiry should be made to see liow far the 

 defect we have pointed out, and any others, might be remedied, so 

 that the canal may be perfected for 20 feet of water throughout, and 

 what would be the cost. 



After such an immense sum of money has been expended upon 

 this canal formed on such a grand scale, with its locks of size 

 and depth to carry through a frigate with all her stores, it is w'orth 

 while knowing why and wherefore no vessels drawing more than 

 twelve feet water can navigate through it. We are of opinion that 

 a comparatively small sum, as compared with what it has already- 

 cost, would make this canal a credit to its projector and a source of 

 profit to the country ; and, in time of war in particular, its advaittages 

 in letting through ships of war and steam boats would confer incal- 

 culable benefit, which in a Russian war could not be too highly 

 prized. 



To revert to the progress oT the work before us, the next object 

 of considerable magnitude and Ijoldness is the formation of the sea 

 lock at the eastern entrance. 



FouIsIoh's Public Buildings. 



SECOND NOTICE. 



Of the buildings here described, that containing the Theatre, Hotel, 

 and Assembly Rooms, is the most important subject in the volume, both 

 on account of its extent, and of the fulness with which it is illustrated. 

 Its principal, or north front, is 270 feet in extent, 70 of which are 

 occupied by its octastyle Ionic portico, which is raised on five steps, 

 and whose columns are thirty feet high. The remaining one hundred 

 feet on each side of this centre, has three tiers of windows (seven in 

 each tier), viz. ground floor, principal, and attic or mezzanine ; all of 

 which openings have dressings to them, those of the ground floor and 

 mezzanine hieed architraves, in addition to which those of the principal 

 floor have both frieze and cornice. The general appearance is good, — ■ 

 has a certain degree of breadth and simplicity that are sufficiently 

 pleasing ; and although it is upon a somewhat lesser scale, this facade 

 very much resembles in its style tliat of our Post-office here in town, 

 while it certainly cannot be said that the architect was in any degree 

 indebted to the latter building, since it appears that his own was com- 

 menced several years before, namely in 1811, the foundation stone 

 having been laid on September lOtli in that year. 



So far, indeed, from suffering very greatly by a comparison with a 

 structure tliat is a national work, and one moreover that cost the 

 country upwards of 230,000/., the Plymouth building— and Plymouth, 

 as Mr. Foulston himself tells us, is, though spirited, proverbially poor — 

 need not shrink from it, as in some respects it will gain by such com- 

 parison, particularly if we bear in mind its priority of date, and the 

 means placed at the disposal of the respective architects. This difler- 

 euce in regard to means becomes all the more striking, when we 



