REPORTS ON TORONTO HARBOUR. 



25 



A graduated standard sounding pole was used for measuring 

 depths. 



A self acting tide guage- was constructed for the purpose of 

 giving a continuous register of every fluctuation in level, and af- 

 fording a means of arriving at the extent, nature, and precise 

 number of fluctuations, of which so little is known, and on which 

 phenomena so much value is placed by many as being the cause 

 of currents in your Harbour. I regret to state, however, that I 

 have as yet been unable to apply this instrument to its purpose, 

 for being unrecognized and unassisted in this service, I could find 

 no position in which to establish it, nor have my means justified 

 me in incurring the necessary attendances for observation during 

 my own absence from the city. 



Thus provided (omitting the last mentioned instrument) I com- 

 menced my second survey on the 27th November, 1850, and was 

 to a certain extent very successful, but during the night some evil- 

 disposed person unknown, removed the iron tripod stationed on 

 the shoal leaving, to my regret, the survey only partially finished, 

 and thus vexatiously disheartened I had on after occasions to 

 adopt other, though perhaps not much less accurate measures. 



Two theodolites were placed at stations as far apart as possible 

 on the Queen's Wharf, their distance being carefully measured, 

 and the points where soundings were made ascertained by a pro- 

 per code of signals and angular intersections. The soundings 

 were in three cases likewise made by the standard rod, and all 

 were carefully reduced to the same datum, the assumed approxi- 

 mate mean level. 



In this manner surveys were again made on the 27th November, 

 1851, the 12th December, 1853, and the 25th April, 1854, each of 

 which are delineated on the accompanying diagram. The sound- 

 ings and contour lines of each survey are shown respectively in 

 different columns as follows : — 



The survey of the 27th November, 1850, in Red. 



27th " 1851, " Blue. 



12th December, 1853, " Black. 



20th April, 1854. " Yellow. 



An examination thereof will show very clearly the progressive 

 advancement of the shoal northward, attributable to the same 

 causes and formed in the same manner as already explained in 

 the paper referred to. The diagram shows the minimum width 

 of the channel between ten feet water lines to be as follows at the 

 several dates : — 



1st October, 1849, 108 yards. 



27th November, 1850, 100 " 



27th November, 1851, 90 " 



12th December, 1853, 77 " 



20th April, 1854, 73 " 



As the north- ten feet water line of the channel is 13 yards south 

 of the Queen's -Wharf, in taking the width of the entrance from 

 the edge of the Wharf 13 yards must be added to each of the dis- 

 tances. Although these figures are not a fair criterion to judge of 

 the rate of advancement of the shoal, seeing that the precise posi- 

 tion of the annual deposit is not always in the line of the minimum 

 width of channel; yet these and the diagram prove very positively 

 the progressive encroachment, and show an average narrowing of 

 the channel of about eight yards annually, thus establishing the 

 truth of the deductions based upon my previous survey as stated 

 4 



in the accompanying paper and illustrated by a model of the en- 

 trance deposited in the museum of the Canadian Institute. 



With these measurements taken with the utmost care, and with 

 others similarly taken at the Isthmus, we are now in a position to 

 answer in very positive terms those questions most particularly 

 referred to in the notice you have issued. 



These propositions are as follows : " The effects which have 

 been produced, or are likely to be produced by the present breach 

 at the eastern extremity of the Bay of Toronto, particularly with 

 reference to the bar at the entrance to the Bay. If prejudicial to 

 the Harbour, suggest the best means of closing it, and of strength- 

 ening that part of the Peninsula against further encroachments by 

 the waters of the Lake." 



First, then, the breach has had no appreciable effect on the bar, 

 for during the period when it was open, the bar has been enlarged 

 in precisely the same manner, through the same causes, and at a 

 similar rate to that in which its formation proceeded when no 

 breach existed. 



Second. Reasoning by analogy from the above, the breach (if 

 again opened) will not likely produce any appreciable effect, bene- 

 ficial or otherwise on the bar. 



Third. The effects produced on the harbor generally by the 

 breach amount only to an unimportant change in the contour lines 

 under 15 feet water in its immediate vicinity, and there only ; 

 which change, when viewed in relation to the harbor as a whole, 

 cannot be considered of any moment whatever. Whilst however 

 it has hitherto been prejudicial to an almost inappreciable extent, 

 and although now completely closed by the westward progressive 

 motion of the beach, it is undoubtedly subject to be opened again 

 by the same causes which formerly produced it, viz. : the destruc- 

 tive action of storms point blank on the shore, and may, by a con- 

 tinuance thereof be dangerously enlarged. It is therefore desira- 

 ble that a recurrence of this breach should be guarded against, 

 and I proceed to submit how in my opinion this may be effected. 



To strengthen this part of the Peninsula two methods present 

 themselves : 1st. The construction of groynes. 2d. The construc- 

 tion of a canal or eastern entrance. Two properly constructed 

 groynes, established on the lines marked in red on Plan No. 2, 

 would effectually and permanently strengthen and protect this 

 part of the peninsula by retarding the progressive motion of the 

 beach, and thus arresting the moving sand and gravel, an accumu- 

 lation would gradually be formed on the outer shore calculated to 

 prevent further encroachments of the lake. 



The construction of a Canal at the Isthmus is a proposition on 

 which, along with the beach, there has been great diversity of 

 opinion, as will be seen from the following extracts from reports on 

 the subject recently published. 



Mr. Shanley says, 28th January, 1853 : — " The very great ad- 

 vantage to be derived from having an eastern entrance to the lake 

 will probably keep this subject so constantly before the public, 

 that the experiment will ere long be tried, more especially as the 

 breach which has lately occurred would seem to have taken the 

 initiative in the matter and ' pointed out the way.' 



" The making of such a channel will be a simple matter of cost, 

 and, once made, a short time will serve to show whether the ad- 

 vantages accruing from it will be sufficient to counterbalance the 

 expense of maintaining it. I have termed it an experiment, and 



