ON THE DRAINAGE-AREA ETC. OF THE KIVER AVON. 181 



liblo conditions, deposit and form accretions, has been shown in the last few 

 years at the mouth of the Avon. In the year 1852 the author assisted in 

 making a very accurate survey of the depths of water at the junction of the 

 Severn and Avon, and of the entrance-channels leading into the latter river. 

 At that date, and indeed from time immemorial, the only available channel 

 for shipping was tlie " North Channel," and there was then a depth of water 

 of from 6 to 10 feet at low water spring-tides. The other channel, the 

 " Swashway," was gradually becoming used by sraaU craft when the tide 

 was in, but there was no low-water channel through it. The depth of the 

 " North Channel " was good up to 1865, when the Irish and other steamers 

 used to land their passengers there. Even in October 1867, Capt. Bedford, 

 R.N., who was surveying the roadstead, says he " found 42 feet of water in 

 this channel, but that in 1871 he only found 8 feet, showing an accumulation 

 of 34 feet, or at the rate of 9| inches a month." 



On a plan accompanying this paper (Plate VII.) is shown a survey made 

 of the entrances to the Avon in 1852, and another made in 1875, together 

 Avith sections taken across the " North Channel " at these dates. In these 

 sections the extent of silting up is shown; and calculations made there- 

 from give a quantity of over a million cube yards of mud deposited here 

 within the last ten years. The top of spring-tide still flows over the surface 

 and adds to tlie deposit, but at neap-tides the new ground can be safely walked 

 across. The greatest depth of the silting up is about 41 feet above the bed 

 of the river in 1852. 



The foregoing remarks on the watershed and on the recorded observations 

 of the tides of the Avon will, it is hoped, have served to give a general 

 knowledge of the natural conditions and capabilities of the river. It remains 

 only necessary to show briefly what has been, from time to time, done in the 

 way of providing for or improving the accommodation for vessels frequenting 

 the port. 



Up to about the middle of the last century tlie shipowners of Bristol seem 

 to have been content with the accommodation the tide (then flowing and 

 ebbing through the centre of the city) gave them. Vessels were then'^com- 

 paratively small, and of a build adapted to lay aground at low water. From 

 the year 1765 to 1800, however, various schemes, including amongst others 

 designs from Smeaton, Ralph Walker, Josias and William Jcssop, were brought 

 forward for providing floating dock accommodation, ending ultimately in the 

 carrying out of a plan by William Jessop. This design took possession of 

 those portions of the rivers Avon and Frome which ran through the city, 

 converting them into the present floating harbour, and substituting a new 

 channel for the tidal water of the Avon to the south of the city. This scheme 

 was projected, carried out, and the docks held by a private company. 



Looking at the character of the public works at that day, the construction 

 of Jessop's works was a very spirited undertaking, and they afforded for a 

 long time accommodation in advance of most other ports. But about the 

 year 1830, when steam -vessels were beginning to take an important place 

 and ships were growing in size, the inadequacy of the old lock entrances, and 

 the difRculties of the navigation of the river, "began to be seriously felt, and 

 various schemes were brought forward to provide accommodation at King- 

 road. Amongst other designs for this purpose was one for a stone pier by 

 Mr. Mylne in 1832, and another by Sir J. MacNeill in 1839, and also one 

 for a floating pier by the late Mr. I. K. Brunei in 1839. None of these, 

 however, were carried out ; and to the discontent felt at the want of adequate 



