162 



♦ KNOWI.EDGE - 



[Aug. 22, 1884. 



result being that the charcoal, purified by the treatment, 

 and increased immensely in oxidising power by the carrying 

 action of the manganese, ads better and lasts longer than 

 wiy ordinary charcoal could. This was proved by one of 

 the early experimentdl filters of manganous-carbon, which 

 ran for two years with ordinary water, and then, on taking 

 to pieces, showed the charcoal perfectly sweet, and with no 

 objectionable appearances under the microscope. The 

 organic impurities had evidently been burnt up, not simply 

 separated by straining: in the latter case, they would 

 have remained in the charcoal." . . . "Manganous- 

 carbon has a developing or increasing power of agency, 

 and improves greatly after short use, as the lower man- 

 ganous oxides gradually assume a flocculent and highly 

 active peroxidised condition. The activity then remains 

 for a long time unchanged, depending, of course, much 

 upon the quality of the water." 



It will be gathered from the above that the block is 

 kept perpetually sweet and clean, by exposure to the 

 influence of the atmosphere, and upon this depends the 

 advantage to be gained by the use of manganous-carbon. 

 Two blocks are supplied, if desired, with each filter, so as 

 to allow of a weekly or fortnightly change for purposes of 

 aeration. 



Type III.— The " Silicited-Carbon Patent Movable 

 Block Filter," as its name implies, is also constructed 

 ■upon the "block " principle, and finds a place here, because 

 it too has survived the severe oideal to which filters are 

 subjected now-a-days. All the working i)ans of the filter 

 «i8e arc made of stoneware, and are hence incorrodible ; 

 the tap is placed on a level with the lowermost stratum of 

 the reservoir, and the entire apparatus admits of being 

 taken to pieces and easily cleansed. The mechanical 

 details of these filters may be readily understood by a 

 reference to Fig. 2G. It may be observed that in Fig. 26, 

 A, the direction of the passage of the water through the 



Vig. 2G.— The SiUoated-Carbon Movable Block Filter. A. Longi- 

 tudinal Median Section. B. Interior view. 



Wock is indicated by a series ot arrows ; this is caused by 

 the novel construction of the block itself, the top and 

 •ed'Tcs of which are made ot non-porous material, so that 

 the water is forced to pass through a maximum amount of 

 the carbon. Toe block, moreover, is bolted down on to an 

 asbestos seating, which is made to form a water-tight joint. 

 The company have informed us that — " SUicated Carbon 

 is an admixture of carbon, iron, silica, and alumina in 

 ascertained proportions ; the carbon being Torbane Hill 

 mineral, from which the oil has been abstracted." Pro- 

 fessor Wanklyn states* that his confidence in the filter is 

 such, that he has passed a solution of strychnine through it, 

 and then drank the filtrate. His explanation ot its action 

 vs. as follows : — " It is an energetic oxidising process, very 

 like the action ot the strongly alkaUne solution of per- 



* The Echo, Aug. 9, 1881. 



manganate with which we are in the habit of boiling the 

 nitrogenous organic matters in drinking-waters. Just as 

 by working the ammonia process we make the nitrogenous 

 organic matter contained in water yield anmionia, so the 

 Silicated Carbon Filter breaks up nitrogenous matters and 

 makes them yield ammonia. In fact, it is possiVjle to work 

 the ammonia process ot water analysis by means of a Sili- 

 cated Carbon Filter, instead of the b liling alkaline solution 

 of permanganate of potash.''* Its lead-removing property 

 has been commented upon by Dr. Bartlett and others, and 

 experiments have shown that it even softens water to an 

 ap[)reciable extent. 



BRITISH SEASIDE RESORTS, 



FROM AN CNCOKYENTIONAL POINT OF VIEW. 



By Percy Russell. 



III. 



PASSING from Bangor, famous for its slates and the 

 tombs of veritable Princes of Wales, with its long 

 crooked streets, in a fertile valley, guarded by steep 

 heights, and proceeding eastwards, we reach Conway, the 

 historic s-eaport of Carnarvonshire. Here can be studied 

 some fine examples of ancient municipal fortifications, and 

 the Castle is allowed to be the finest example of such 

 structures in Great Britain. Some of the walls are nearly 

 four yards thick. A " sight " of this place is the Plas 

 Mawr, i.e , the Great Mansion — a stately pile dating from 

 Elizabeth, and most curiously adorned without and within 

 by heraldic devices. Conway contains the tomb of the 

 Great Llywelyn, and to Welshmen is on that account a 

 sacred city. The river is here, at spring-tide, full half a 

 mile wide, and from the days of the Romans has had a 

 rejjutation for pearls. The coast now takes a sharply 

 northern direction, and brings us to one ot the nineteen 

 great headlands of England and Wales, Great Orme's 

 Head. This striking natural feature lies about five miles 

 only north east of Conway, and is an immense mass ot 

 liraistone rock, rising t > a height of nearly 700 feet, and 

 surmounted by a lighthouse. East ot this remarkable 

 feature of the coast is Llandudno, with its soft airs and fine 

 bathing, and passing Abergele and Rhyl, and still working 

 eastward, we now reacli the noble tidal estuary of the river 

 Dee, which the ancient Britons', by the way, regarded as 

 a sacred stream. The estuary ot the Dee is nine miles 

 long, and at seasons full six wide, and is hallowed to the 

 students of Milton as the fatal shallow where " Lycidas," 

 or, in plain English, Mr. King, the friend of the poet, 

 sufTered shipwreck and death. 



Parkgate, little known to the ordinary tourist, is a 

 small watering-place competing with the better-known 

 ^Mersey resorts for visitors from Liverpool. No purer air can 

 be found in England than that blown over the beautiful 

 Dee and down from the Welfh hills, while the lovely 

 scenery of North Flintshire and the splendid expanses ot 

 the estuary here give Parkgate a strange charm for all who 

 love Nature in her pict'ire-que phases. At times, indeed, 

 and especially at low water, the estuary becomes in great 

 part a vast waste ot s-ind and ooze, and then aptly enough 

 reminds one of the dirge-like song in Kingsley's famous 

 Chartist novel or political pamphlet — 



Oh, Mary, go and call the cattle home, 

 Across the sands of Dee. 



Seen, however, with the tide in, the estuary is a grand 



* In a paper read before the " British Medical Association," at 

 Sheffield. 



