TJkANSACtlOXS OF SECTION G. 761 



same year, between Cornwall and St. John's, Newfoiuidland, a distance of 2,000 

 miles. In the year 1902 signals were transmitted from England to the Baltic and 

 the Mediterranean, which had thns 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 sufhcient energy. The question of ' syntonism,' by which it 

 is proposed to assure the secrecy of messages, appears to be still subjudice, but is 

 undergoing further investigation. 



There appears to be a practical field for the development of ' wireless tele- 

 graphy,' more especially where ordinary telegraphy cannot be applied, as, for in- 

 stance, between shore and ships at sea or between one ship and another. 



The Marconi Wireless Telegraph Company have obligingly 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 passeuger-steamers already furnished 

 Avith the Marconi apparatus, thus affording evidence of its application to practical 

 purposes. 



The system of ' wireless telegraphy ' by Sir Oliver Lodge and Dr. Mnirhead 

 has, I understand, been htted to cable steamers of the Eastern Extension Tele- 

 graph Company, to enable communication to be made with their cable stations. 



SpAoage DiiposaL 



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 

 enabled to make a brief reference to tbe 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 filtration processes, ten of theoriginal 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 filters containing 3 feet in depth of tine 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, 

 witii 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 Irom -{% inch to ^ inch 

 diameter. The liquid is ' rained ' on to the surface by spray jet's, and the beds 

 are used generally in shifts of two hours each for eight hour.s 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. 



LiverjJool Docks. 



Althouffh 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 tlie 

 Kibble be taken into consideration, there are few areas of greater interest to tbe 

 hydraulic engineer than these rivers with the shores that bound them, and few 

 in wliich stranger changes in land level have occurred Avithin historic times. In 

 the Itinerary of Ptolemy, the Ribble is named immediately after the 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 Inst.(!.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 Valleys and Later Deposits in the neighbourhood of Liverpool.' 



Evidence of the gradual sinking of the land is given by the very interesting 

 discovery in 1850 of a Roman bridge at AVallasey Pool, Birkenhead. After 

 excavating fourteen feet, the workmen came upon a bridge of solid oak beams, sup- 

 ported in the centre by stone piers and resting at the ends upon the solid rock at 



