572 



SCIENTIFIC NEAA^S. 



[June 15, I? 



have taken to lower the bed of the river to its present 

 level, in order to show the great age of these relics, and 

 in conclusion gave a minute description of the researches 

 in Kent's Cavern. 



SOCIETY OF ENGINEERS. 

 At a meeting of the Society of Engineers, held on June 

 4th, Mr. A. T. Walmisley, President, in the chair, a paper 

 was read on " The Acton Main Drainage Works," by Mr. 

 C. Nicholson Lailey. 



A special interest attached to this paper, on account 

 of its containing a fall description of the successful 

 system of the International Purification Company, which 

 system Acton is the first town to adopt. 



After glancing historically at the origin of the Acton 

 Drainage Works, and showing that neither a sewage- 

 farm nor the lime process were admissible, the site of 

 the works being near the Bedford Park Estate, and close 

 to an intended public recreation ground, a position 

 which made the entire absence of foul odours, as well 

 as a clear and pure effluent, absolutely essential, the 

 paper gave an account of the formation of the sewers 

 under disadvantageous circumstances, and the details of 

 the works. These are situated on a triangular piece of 

 ground about 5 acres in extent, and comprise precipitating 

 tanks, the chemical buildings, and the pumping station. 



The drainage of Acton is divided into two sections, a 

 high and a low level. The high-level sewage flows into 

 the precipitating tanks by gravitation, but the low-level 

 requires pumping. Underneath the pumps is a storage 

 tank for the low-level tewage, capable of holding 

 50,000 gallons. The precipitating tanks are three in 

 number, and will hold 138,000 gallons of sewage each. 

 In addition to these are two smaller tanks, one of which 

 contains the magnetic spongy carbon filter bed, and in 

 the other it is intended to construct another similar 

 filter when increased population renders it necessary. 



The "magnetic process" consists (c) in precipitation of 

 the solids, and (2) in filtration of the effluent through a 

 bed containing a layer of " magnetic spongy carbon." 

 This " magnetic carbon " is a hard material of such re- 

 markable oxydifing and aerating powers, that the 

 effluent, after passing through it, is, to quote an inde- 

 pendent report of Dr. E. L. Jacob, Medical officer of 

 Health to Surrey Combined Sanitary District, " superior 

 to many potable well waters." The precipitant used is 

 ferrous carbonate, and the mode of applying it is to 

 grind it up into a thin slurry with water or sewage, 

 and then to run this liquor into the sewage as it flows 

 into the precipitating tanks. After allowing the sewage 

 in the tank to settle for about three hours, the effluent 

 is passed through the magnetic spongy carbon filter bed, 

 from which it issues in a state of almost perfect purity, 

 and flows into the Thames. The sludge, which is very 

 dense, is then drawn off" into the sludge well, whence it 

 is pumped into the presses. The amount of sludge ob- 

 tained per week is 18 tons, and, when pressed, this 

 gives 4 tons 10 cwt. of sludge cake, which has all been 

 sold up to date, and fetches 30s. per ton. 



The author considered the magnetic process advan- 

 tageous over all others, because the effluent is not spoilt 

 by the use of lime, the manurial value of the sludge is 

 much increased, the nuisance which exists at most sew- 

 age works where lime is used is not created, the Thames 

 is not polluted by it. 



The Acion Local Board had at first grave doubts of 

 the efficacy of any filtering bed for sewage, but experi- 



ments for a period of nine months convinced them that 

 the " magnetic process " was all that could be desired, 

 and they consequently entered into a contract with the 

 International Purification Company for the supply of 

 their material for a term of five years. 



The author and the Acton Local Board, with good 

 reason, pride themselves that after careful investigation 

 they have selected not only the most recent, but the 

 most highly developed of modern sewage processes, at 

 once the most perfect and the most economical. In the 

 tanks the solids are removed and the fluid defecated and 

 deodorised, and in the filter bed the deodorised fluid is 

 purified from the organic matter in solution, so that the 

 effluent produced is the most perfect yet obtained ; and 

 these advantages are had without the great expense 

 attending the use of land for a sewage farm, which, 

 they contend, is no longer a necessity. 



GEOLOGICAL SOCIETY OF GLASGOW. 

 At the concluding meeting of the thirtieth session, held on 

 May 31st, Mr. John Young-, F.G.S., exhibited a specimen of 

 the bed of intrusive dolerite found in connection with the 

 carboniferous strata in which (he fossil trees are imbedded 

 at Victoria Park, Whiteinch. In one of the veins of the 

 igneous rock recently exposed, and which has been found 

 to pass through the roots of one of the trees, the remains 

 of a glassy surface on either face where it had cooled 

 most rapidly are found. These glassy faces show a 

 spherulitic structure, in which the spheres have polygonal 

 outlines from pressure contact when the rock was still in 

 a fluid condition. A finely radiated sfrncture has also 

 been developed, much like that seen in the Arran 

 spherulitic pitchstones At Whiteinch, however, the 

 rock shows the radiation only in parts, owing to the de- 

 vitrification which has taken place long subsequent to its 

 injection. 



Mr. Robert Dunlop read an interesting account of a 

 peat bed he had lately discovered, surrounded by boulder- 

 clay, in the neighbourhood of Airdrie, and the presence 

 of which in its peculiar position opened up many geologi- 

 cal points of considerable importance. 



The Hon. Secretarj' read a paper forwarded by Mr. 

 James Bennie, of the Geological Survey, on "The Re- 

 demption of Sandstone Quarries," in which the author 

 showed how the most unpromising fields to the geological 

 eye, in the shape of worked-out or long-disused sandstone 

 quarries, might be made to yield treasures of old-world 

 life in the shape of plant remains, and portions of scor- 

 pions, eurepterids, and other air-breathing creatures, 

 although, curiously enough, no traces of the insects on 

 which these animals preyed had as yet been discovered. 

 There was still ample scope for the diligent and sharp- 

 eyed collector to make important discoveries in this 

 direction. 



THE ARCH^OLOGICAL INSTITUTE. 

 At the monthly meeting held on June 7th, Mr. 

 J. T. Micklethwait, F.S.A., in the [chair, the 

 papers read were (i) "On the Discovery of 

 cf a Curious Structure, supposed to be the Cell of an 

 Anchorite," at Ongar, between Epping and Chelmsford, 

 Essex, by the Rev. E. S. Dewick ; and (2) "On Norman 

 Masonry, and Masons' Marks," by Mi". J. Park Harrison. 

 Each of the two papers was followed by a discussion, in 

 which Messrs. Micklethwait, Hope, Scarth, and Walford 

 took part. 



