REPORTS ON TORONTO HARBOUR. 



33 



The sectional area of the eastern channel, 200 feet 

 wide by 12 feet in depth, would be 2,400 



Still leaving a surplus in favour of the western channel 



of. 18,950 



By reducing these amounts to the lowest fraction, the propor- 

 tion of the sectional area of the eastern channels to that of the 

 western, would be, as nearly as possible, one-ninth. 



From the above calculations, it may be inferred that, during an 

 easterly or westerly gale, there would still be a current flowing 

 out of the Harbour at the western channel. In an easterly gale, 

 there would be a current from the east to west through the eastern 

 entrance, and vice versa, in either case the current into, or out of, 

 the Harbour, through the western channel, would be diminished 

 one-ninth, and the consequent scouring effect on the western chan- 

 nel would be lost in this proportion. Whether this would have 

 the effect of destroying the balance which has been maintained 

 for so long a period, is a matter of opinion. 



Supposing that the point of the bar advanced eight feet per year 

 across the channel, which, however, it does not, the encroachment 

 would be nine feet instead of eight feet. When the present con- 

 tract for the extension of the Wharf westward 400 feet is com- 

 pleted, I am of opinion that the back current will be sufficient to 

 scour the increased channel 400 feet wide, even in the event of an 

 eastern entrance being constructed. 



The current through the western channel, caused by the dis- 

 placement of the water by steamers passing at full speed, is very 

 considerable for the time it lasts, and has a good scouring effect, 

 tending to prevent the encroachment of the Bar on the channel. 

 If an eastern entrance is constructed, a portion of this effect will, 

 of course, be lost, the proportion in this instance it would be diffi- 

 cult to ascertain. I do not, however, think that the loss would be 

 so great in any case, as to endanger the filling up of the western 

 entrance. 



With regard to the arrest of the deposit on the bar, by the con- 

 struction of piers or groins along the shores of the Peninsula, it 

 can only be considered as temporary ; and to be effectual, would 

 have to be renewed and kept in repair year by year, an expense 

 which frill be found as much, if not greater than using the dredge. 



In Sir Charles LyelFs Principles of Geology, page 318, speak- 

 ing of the encroachments on the south coast of England, it is 

 stated — 



" It appears, from the observations of Mr. Palmer and others, 

 that if a pier or groin be erected anywhere on our southern or 

 south-eastern coast, to stop the progress of the beach, a heap of 

 shingles soon collects on the western side of such artificial bar- 

 riers. The pebbles continue to accumulate till they rise as high 

 as the pier or groin, after which they pour over in great numbers 

 during heavy gales." 



According to the old saying, "prevention is better than cure," 

 if the true remedy requires to be pointed out ; and admitting that 

 the continued deposit on the Peninsula is caused by the " debris" 

 from the Scarboro' heights, expend the money that would be 

 wasted in the construction of piers or groins, in the protection of 

 the base of the Scarboro' heights, and the object is attained ; but 

 the wisdom of this course is to be doubted ; the deposit from this 

 source is not so great as is imagined, and it must be borne in 

 5 



mind, that a considerable portion of the deposit on the Peninsula 

 is removed by the under-current not to be replaced, except by this 

 very supply from the Scarboro' heights, which is considered so 

 great a nuisance — taking all matters into consideration, this sup- 

 ply, on the contrary, will, on reflection, be considered advantage- 

 ous in preserving the Peninsula, and consequently preserving the 

 Harbour. As to "making a permanent opening into the Lake 

 from Ashbridge's Bay," it is a question that can be well post- 

 poned, as the present opening is quite sufficient for the require- 

 ments of that portion of the Harbour ; and in all future specula- 

 tions on the subject, it would be advisable to view it as likely to 

 form a separate Harbour altogether from the present one ; as 

 such, with an entrance into Toronto Harbour duly protected with 

 gates, to keep the mud which has collected there for ages from de- 

 stroying Toronto Harbour, an excellent Harbour may be con- 

 structed by running out piers into deep water, as recommended for 

 the eastern entrance of Toronto Harbour ; the cost of such work is 

 stated in the general estimate ; though the expense is not advis- 

 able, as all available funds will be found little enough for preserv- 

 ing and maintaining a Harbour, which, up to the present time, 

 stands unrivalled on the great Lakes of this Continent. 



KIVAS TULLY, 



Civil Engineer. 

 Toronto, May 3d, 1854. 



ESTIMATES. 



For the Preservation of the Harbour. 



1st. Closing the River Don, and diverting the cur- 

 rent into Ashbridge's Bay £7,500 



2d. The strengthening of the Narrows of the Pen- 

 insula 2,500 







£10,000 



For the Improvement of the Harbour. 



1st. Closing the River Don £7,500 



2d. Constructing the eastern entrance 200 feet wide 

 and 12 feet in depth, piers 40 feet wide, running 

 into 20 feet of water 60,000 



£67,500 



Improving Ashbridge's Bay. 



1st. Constructing channel in eastern end of Ash- 

 bridge's Bay, with piers, &c £50,000 Q 



2d. Constructing canal, with gates, &c, 60 feet wide, 



10 feet of water, where shown on the Map 10,000 



£60,000 



Toronto, May 3d, 1854. 



KIVAS TULLY, 



Civil Engineer. 



