1845. J 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL 



drawing a dppth of water of from ^7 feet 9 innlips to IS feet c;in ns- 

 cend tlie Cly<li' at liigli water to tlie liarhuur of Glasgow; botli Eist 

 and West Indinin.in ,iiid all tlie large American vessels, &c., now sail 

 up and (liscliarge tlieir cugoes in Glasgow ; while it may he observed 

 that in 1755 the dp|)lh of water in the Clyde w<Mild only allow vessils 

 to ascend op to Glasgow harbour drawing from 3 feet 3 inches to 3 feet 

 6 inches of water. 



The amount of shipping now frpqnenting the Iiarbour of Glasgow 

 annually is abmit 1,20U,UU0 tons. Tlie amount of revenue arising from 

 river and harhnur dues is now annu lUy about from £10,000 to £15,000 

 — in 1771 it was only i'l,071 per annum. 



There are eipployVd in deepening and improving the Clyde five 

 deepening niailiines, a steam tug boat, two diving bell boats, with 

 about IGo piinisk The value of the whole working raachiuery may be 

 taken at £39,000. 



The following are the quantilies of sand, mud, clay and gravel 

 dredged up from (he bed of the river Clydf- during the last four years 

 by tlie five steam dredging boats, and also the amount of the expense. 

 As there is more dredging in the river Clyde than in any other river 

 in the world, it may perhaps be interesting to state the following 

 practical results. 



To pri-servp the present depth of water in the harbour of G'asgr.w 

 and the river Clvde requires an annual dredging of about fn.in 160,000 

 cubic y.irds to 180,000 cubic yards, taking this at bd. per cubic yard, 

 on 180,000 cubic vards amounts to £o,000 annually ; this is on a river 

 liue IS Knglish miles in length. 



1st. Til- improvement of the navigation of the river Clyde is due to 

 the construction of jetties, which fixed the channel and increased the 

 scouring power of the river. 



2nd. The construction of longitudinal dykes, by wliich the velocity of 

 the water was equalized, thereby removing the shoals and pools formed 

 by the jetties. 



3rd. To the dredging machinery and diving bells, in removing all 

 kinds of shoals, banks, and bars from the channel of the navigation which 

 the works of the jetties and longitudinal dykes could not accomplish 

 by the increased scouring power of the river. 



Dredge boat No. 1 commenced in 1824 10 horse power. 



Do. No. 2 do. 1826 16 do. 



Do. No. 3 do. 1830 16 do. 



Do. No. 4 do. 1836 20 do. 



Do. No. 5 do. 1841 22 do. 



In concluding these very few and short observations, I beg leave to 

 mention th.it I shall be very happy at any time to give the Institute a 

 ninute detailed account of the whole or any part of the works which 

 ave been done to improve the navigation of the river Clyde; or the 

 dredging machinerv, diving bells, &c. ; or the tides, currents, or velo- 

 city of the water ; for, unfortunately, nothing of the kind lias yet been 

 published, either in Great Britain or elsewhere, embracing all these 

 subjects. 



The improvptnpnt of the tidal harbours and tidal river navigation 

 is of national importance to every countrv, and more particularly since 

 the application of steam to navigation, because steamers can so rapidly 

 navigate every river where sutiieient depth of water exists ; so im- 

 portant is this considered that at this very moment a Royal Tidal 

 Commission is now sitting in the Admiralty in London examining into 

 the improvement of all the tidal harbours and river tidal navigations 

 of England, Ireluid, and Scotland, also into the invasions and encroach- 

 ments which hive been made upon many of the tidal river navigations 

 and tidal h.irbonrs by embanking and shutting out the sea water, and 

 which has in many instances ruined several of the English harbours. 



William Bald. 

 Paris, June 2, 1845. 



Stattmt-ni of Sums sjient hi the Improvements of Rivers. 

 The Shannon, Ireland .. .. .. £350,000 



The Clvde .ihd the Port of Glasgow .. .. 500,000 



The Bovne and the Po.t of Drogheda . . . . 50,000 



The Liffey and the Port of Dublin, including quavs, &c. 1,250,000 



Kingston, six miles below Dublin (south side of the bay) 600,000 



Howth, nine miles below Dublin (north side of the bay) 500,000 



In addition to the above we have been able to obtain some valuable 

 information relative to the cost of dredging and quantity of work per- 

 formed by mo hine on the river Clyde. 



The foUowini; iiatenients have been taken from the official records of the 

 Clyde trustees. Hut no account can he foiiml in their books of the annual 

 quantities of mali rial wliii h lias been dredged up in the harliour of Glasgow 

 and the Clyde preiions to 1838, and which was one year before Mr. Ijald 

 wts appointed euglueer. 



23.5 



F.r tract showing tlie amount of I lie Performance of the Lalouring Force, and 

 time of the Five Sleam Dredije Hoots on tlie river Clyde, by Manual Labour 

 propelling forward, and also by Steam Power propelliuy forward. 



By Manual Labour Working Forward. 



IRIS 



1840 

 I8J1 



By Steam Power Working Forward. 



Total Amount of Erravntion ilrpihicd from the bottom of the river Clyde and 

 harbour of (llasi/ow iti ( he Jotlowing Years. 



Total quanUtv excavated 101,''45Punl f.oa.ls, fi-oni the beginning of 1838 to the end one44 

 The Velocity nf the Water in the River. 



" The mean velocity of four sets of observations of the water passing down 

 the Clyde, from the harbour of (jiasgow to the junction of the Cart river 

 with the Clyde, in ordinary lair weather may be taken at 1576 yards per hour, 

 and the ascending current at 771 yards per hour; and from the junctiim of 

 (lie river Cart with the Clyde, to opposite Dunbarton Castle, the mean of 

 five observations assigns the descending velocity of the Clyde at 1 mile 1069 

 yards per hour, and the ascending current at 1561 yards per hour. 



" 111 the river Clyde during higli floods, immediately below the harbour of 

 Glasgow, I have found the velocities of the descending currents run at the 

 rate of 2 miles 1613 yards per linur; and in the narrow parts of the river 

 3 miles 1148 yards per hour; this was in the middle of the river, and at the 

 water's surface."' 



The Rise oj the Tide and the Time of Ebbing and Flowing. 



String Tides. 



The mean result of six observations, taken on the 18th, 19th and 2nth March, 1840, a 



the rise and fall of the tide at the following places, was as follows (full moon March 18 :— 



Ft. In. 

 Mean rise and fall of six tides in the harbour of Glasgow .. 8 4 

 Ditto at Clyde Bank, 6 miles 8li6 vards from Glasgow Bridge 8 



Ditto at Bowling )!ay, 10 miles 1166 yards from ditto.. .. 8 9 



Ditto, 18 miles 1166 yards from ditto 10 5 



H. M. 

 Mean rime of flowing in Glasgow Harbour .. .. .. 5 10 



Dittoof ebbing in ditto 7 13 



Meanlimeof flowing at Clyde Dank 5 18 



Ditto of ebbing at ditto 7 6 



Mean lime cif flowing at Bowling Bay 8 24 



Ditto of ebbing at ditto 6 66 



Mean time ot flowing at Port Glasgow 6 6 



Ditllo of ebbing at ditto 6 I 



Neap Tides. 

 Taken at the following places on the 25th, 26th, and 27th March, 1840. 



Ft. lo. 

 Mean result of six observations of the rise and fall of the tide 



in the harbour of Glas|(ow 6 3 



At Clyde Bank, mean of six Udes 5 10 



At Howling, ditto ' 5 II 



Al Port Glasgow, ditto 6 I 



H. M. 



Mean time of flowing at Glasgow 5 14 



Dillo of ebbing at ditto 7 16 



Mean time of flowing at Clyde Bank S 43 



Ditto 01 ebbing at ditto 7 I 



Mean lime ot flowing at Bowling 8 52 



Ditto ofebbing at dillo 6 37 



Mean time of flowing at Port Glasgow 6 26 



Ditto of ebbing at ditto 6 59 



31* 



