September 24, 1903] 



NATURE 



509 



last, in the ninety-fourth year of his age, of that eminent 

 scientific aeronaut, Mr. James Glaisher, F.R.S., who in 

 1863 made his famous ascent to an altitude of seven miles, 

 and who described at the Newcastle-upon-Tyne Meeting in 

 that year, in an evening lecture, the balloon ascents made 

 for the British Association. 



Wireless Telegraphy. 



In addressing this Section I feel that I ought to say a 

 few words on the subject of " wireless telegraphy." With 

 regard to signalling Signor Marconi certainly seems to have 

 made progress. In January, 1901, signals were conveyed 

 from Poldhu in Cornwall to the Isle of Wight, a distance 

 of 200 miles, and in December of the same year, between 

 Cornwall and St. John's, Newfoundland, a distance of 2000 

 miles. In the year 1902 signals were transmitted from 

 England to the Baltic and the Mediterranean, which had 

 thus passed over both sea and land. It seems to be not 

 improbable that signals can be sent any distance, so long as 

 the sending station can develop sufficient energy. The 

 question of " syntonism," by which it is proposed to assure 

 the secrecy of messages, appears to be still sub judice, but 

 is undergoing further investigation. 



There appears to be a practical field for the development 

 of "wireless telegraphy," more especially where ordinary 

 telegraphy cannot be applied, as, for instance, between shore 

 and ships at sea or between one ship and another. 



The Marconi Wireless Telegraph Company have oblig- 

 ingly furnished me with a list of eighteen land stations 

 fitted on the Marconi system for commercial ship signalling, 

 together with a list of forty-three passenger-steamers 

 already furnished with the Marconi apparatus, thus afford- 

 ing evidence of its application to practical purposes. 



The system of " wireless telegraphy " by Sir Oliver Lodge 

 and Dr. Muirhead has, I understand, been fitted to cable 

 steamers of the Eastern Extension Telegraph Company, to 

 enable communication to be made with their cable stations. 



Sewage Disposal. 



The bacterial treatment of sewage is receiving much 

 attention, and by the courtesy of Mr. J. Corbett, 

 M.Inst.C.E., the Borough Engineer of Salford, I am en- 

 abled to make a brief reference to the system of sewage 

 treatment now carried on at the Salford Corporation Sewage 

 Works, adjoining the Manchester Ship Canal. Twenty 

 years ago the works were constructed with precipitation 

 tanks for lime treatment of the sewage. After fourteen 

 years of experiments with various precipitation and filtra- 

 tion processes, ten of the original precipitation tanks were 

 formed into two large tanks in which precipitation takes 

 place with the aid of milk of lime and salts of iron. The 

 other two original tanks were converted into six roughing 

 fillers containing 3 feet in depth of fine gravel, to intercept 

 particles which have escaped the precipitation process, and 

 which would tend to choke the final filters. The final 

 purification is on bacteria beds or aerated filters, with an 

 open false floor of perforated tiles and large open culverts 

 giving constant ventilation through the beds, some of which 

 are filled to a depth of 5 feet and others to a depth of 8 feet 

 with crushed clinkers of from y\ inch to f inch diameter. 

 The liquid is " rained " on to the surface by spray jets, 

 and the beds are used generally in shifts of two hours each 

 foi eight hours a day in dry weather and for twenty-four 

 hours during heavy rainfall. An average quantity of from 

 400 to 500 gallons of sewage per square yard per day is 

 treated with satisfactory results. 



Liverpool Docks. 



Although there may seem little of interest in the vast 

 areas of sand which separate Southport from the sea, yet 

 if the whole sea coast from the Dee to the Kibble be taken 

 into consideration, there are few areas of greater interest 

 to the hydraulic engineer than these rivers with the shores 

 that bound them, and few in which stranger changes in 

 land level have occurred within historic times. In the 

 Itinerary of Ptolemy, the Ribble is named immediately after 

 th>' Dee, the Mersey being omitted altogether. 



-At the meeting of this .Association at Liverpool in 1896, 

 reference was made to these matters, not only by the 

 President of this Section, Sir Douglas Fox, Past President 



NO. 1769. VOL. 68] 



Inst.C.E., but also in papers read, one of which, by Mr. 

 T M. Reade, F".G.S., is entitled " Oscillations in the Level 

 of the Land, as shown by the Buried River N'alleys and 

 Later Deposits in the neighbourhood of Liverpool." 



PLvidence of the gradual sinking of the land is given by 

 the very interesting discovery in 1850 of a Roman bridge 

 at Wallasey Pool, Birkenhead. After excavating fourteert 

 feet, the workmen came upon a bridge of solid oak beams, 

 supported in the centre by stone piers and resting at the 

 ends upon the solid rock at the sides of the creek. The 

 length of the bridge was 100 feet and its width 24 feet, 

 and the beams were each 33 feet long, 18 inches wide, 

 and 9 inches thick ; there were 36 beams formed into 12 

 compound beams, each 27 inches in depth. Careful draw- 

 ings of this bridge were made by Mr. Snow, an engineer 

 employed on the work then in progress. The drawings 

 show that the rocky bed of the stream was some 13 feet 

 below the bridge, which was itself about 16 feet below 

 present high-water level. 



F^ormerly Liverpool was one of the ports subordinate to 

 the Comptroller of Chester, and is styled in the Patent " a 

 creek in that port." 



The first Act of Parliament authorising the construction 

 of Dock works was obtained in 1709, and in 1853 the water 

 area of the docks had been increased to 178 acres. Since 

 i8i;3 the progress has been much more rapid, especially 

 within the last thirty years. The total area of the docks 

 and basins at Liverpool and Birkenhead is now 566 acres, 

 whilst in connection therewith there are rather more- than 

 35 miles of quayage. The marked tendency in recent years 

 to increase the' length, beam, and depth of ocean-going 

 steamers has necessitated the provision of dock accommoda- 

 tion for a much larger class of vessel than formerly existed ; 

 and during the last decade works of great magnitude have 

 been successfully carried out by the Mersey Docks and 

 Harbour Board,' under the able' direction of the late Mr. 

 G. F. Lyster, M.Inst.C.E., and, since his death, of his 

 son, Mr. Anthony G. Lyster, M.Inst.C.E. In the northern 

 section a new graving-dock has been constructed, extensive 

 additions have been made to the Canada and Huskisson 

 Docks, whilst the difficult work of constructing new river 

 entrances has also been satisfactorily comp'leted. In the 

 southern section, the Queen's Dock has been enlarged and 

 other important additions have been executed and brought 

 into use. 



To convey some idea of the magnitude of the works 

 executed, it may be mentioned that the amount expended 

 by the Dock Board in the extensions above indicated 

 exceeds 1,750,000/. 



The largest lock connected with the port of Liverpool 

 is the Canada, 600 feet long by 100 feet wide, the sill being 

 14 feet below the datum of Old Dock sill, which datum is 

 4 feet 8 inches below Ordnance datum, or mean sea-level. 

 Two large river-entrance locks into the Brunswick Dock 

 are now approaching completion, the larger lock having a 

 length of 350 feet and a width of 100 feet, with a sill 19 feet 

 6 inches below the datum of Old Dock sill. 



One of the striking features in connection with the 

 port of Liverpool is the difficult and extensive work con- 

 nected with the dredging operations at the Mersey Bar. 

 Since the commencement in 1890, to August, 1903, no less 

 than 72,000,000 tons of material have been dredged and 

 removed from the Bar and sea channels, and the average 

 quantity for the last five years has been in round figures, 

 7,000,000 tons per annum. The total tonnage of the port 

 for the year ended July i, 1903, was 13,308,305, and the 

 receipts therefrom amounted to 1,185,066/., exclusive of 

 graving dock and other rates. 



Irrigation. 

 This being the first Meeting of the British Association 

 since the completion of the Assuan dam, which I had the 

 opportunity to inspect when visiting Egypt in the early part 

 of this year, I should like to devote to it a short portion 

 of my .Address. Those who desire to learn all about that 

 work in detail I would refer to the papers (to which, 

 indeed, I am indebted for my information on the subject) 

 read before the Institution of Civil Engineers on January 27 

 last by Mr. .Maurice Fitzmaurice, C.M.G., M.Inst.C.E., 

 who had charge of the work on behalf of the Egyptian 

 Government from its commencement in 1898 until 

 December, 1901, and by Mr. F. W. S. Stokes, M.Inst.C.E., 



