April 7, 1882.] 



KNOWLEDGE 



487 



MAGj^ZINEofS^ENCE 



P LAlNLT^f ORJED -EXACTLVDESCR IBED J 



LOI\'DON : FRIDAY, APRIL 7, 1882. 



Contents of No. 23. 



PAGB 



Doniostic Ventilation. A Lesson 

 from the Coal-Pils. liy W. 

 Mattieu WilUams 487 



Found Links. Bv Dr. Andrew 

 WiUon, F.It.S.E.;P.L.S. (/«»»(.) ISS 



Xotes on Rowing. By an Old Club 

 Captain lOl 



The Crystal Palace Electrical E.tlii- 

 bilion. Kichth Notice. (/«»*(.) 402 



The ISrcat Pyramid. Bv the Editor 493 



Phcilojiniphv for Amateurs. By A. 

 nrothera.'F.K.A.S. Part HI. ... 401 



Brain Trouble?. Irritability 403 



Does the Luminous Mixture of Blue 

 and Yellow make Green Light.' 

 Bv Lieut.<;olonel W. A. Ross, 

 late R.A. (lUminiUJ) 496 



PAQB 



Weather Diagram. For Week ending 



Saturday, April 1 J9" 



Amalgams 497 



Silvered-Glass Telescopes -498 



Prehistoric Research in Russia 498 



Morning "Work 499 



A Panther in Vermont 499 



JeUv Pish 499 



Intelligence in Birds 499 



Fairy " Folk-Loro " of Shctknd ... 500 



Con-e-pondence ../ 501-504 



Queries 603 



1 Replies to Queries 502 



! Answers to Correspondents 503 



I Our Mathematical Column 504 



Our Chess Column 50.5 



, Our ^Vlust Column 506 



DOMESTIC VENTILATION. 



A LKSSON FROM THE COAL-PITS. 



Bv W. Mattieu Williams. 



"ITTE rtMiuiru in our houses an artificial temperate 

 * V climatt; wliicli shall be uniform throughout, and 

 at tlie same time we need a gentle movement of air that 

 sliall supply t!ie retjuirements of respiration without any 

 gusts, or draughts, or alternations of temperature. Every- 

 body will admit that these are fundamental desiderata, 

 but whoever does so becomes thereby a denouncer of opcn- 

 gi-ate tire-places, and of every system of heating which is 

 dependent on any kind of stoves with fuel burning in the 

 rooms that are to be inhabited. All such devices concen- 

 trate the heat in one part of each room, and demand the 

 admission of cold air from some other part or parts, thereby 

 violating the primary condition of uniform temperature. 

 The usual proceeding effects a specially outrageous violation 

 of this, as I showed in my last paper. 



I might have adtlcd domestic cleanliness among the 

 desiderata : but in the matter of tire-places, the true-bom 

 Briton, in spito of his fastidiousness in respect to shirt- 

 coUais, itc, is a devoted worshipper of dirt. No matter 

 how elegant his drawing-room, he must defile it with a 

 coal-scuttle, with dirty coals, poker, sho\el, and tongs, 

 dirty ash-pit, dirty cinder.s, ashes, and dust, and he must 

 amuse himself by doing the dirty work of a stoker towai'ds 

 his " cheerful, companionable, pokeable '' of>en fire. 



It is evident that in order to completely fulfil the above- 

 named requirements, we must, in winter, supply our model 

 residence with fresh artificially-warmed air, and in summer 

 with fresh cool air. How is this to be done ? An approach 

 to a practical solution is afforded by examining what is 

 actually done under circumstances where the ventilation 

 problem presents the greatest possible difficulties, and 

 where, nevertheless, these difficulties have been effectually 

 overcome. Such a case is presented by a deep coal mine. 

 Here we have a little working world, inhabited by men 

 and horses, deep in the bowels of the earth, far away 



from the air that must be supplied in sufficient quan- 

 tities, not only to overcome the vitiation due to 

 their own breathing, but also to sweep out the deadly 

 gaseous emanations from the coal itself. Imagine your 

 dwelling-house buried a quarter of a mile of perpen- 

 dicular depth below the surface of the earth, and its walls 

 giving oft" suttbcatiiig and explosive gases in such quantities 

 that steady and abundant ventilation shall be a matter of 

 life or death, and that in spite of this it is made so far 

 habitable that men who spend half their days there retain 

 robust health and live to green old age, and that horses 

 after remaining there day and night for many months 

 actually improve in condition. Imagine, further, that the 

 house thus ventilated has some hundreds of small, very 

 low-roofed rooms, and a system of passages or corridors 

 with an united length of many miles, and that its in- 

 habitants count by hundreds. 



Such dwcllLngs being thus ventilated and rendered habit- 

 able for man and beast, it is idle to dispute the practical 

 possibility of supplying fresh air of any given temperature 

 to a mere box of brick or stone, standing in the midst of 

 the atmosphere, and containing but a few passages and 

 apartments. 



The problem is solved in the coal-pit by simply and 

 skilfully controlling and directing the natural movements 

 of unecjually-heated \olumes of air. Complex mechanical 

 devices for forcing the ventilation by means of gigantic 

 fan-wheels, itc, or by steam-jets, have been tried, and are 

 now generally abandoned. An inlet and an outlet are pro- 

 vided, and no air in allowed to pass inwards or outwards 

 by an;/ other course than that whieh has been pre-arranf/cd 

 for the purposes of efficient ventilation. I place especial 

 emphasis on this condition, believing that its systematic 

 violation is the primary cause of the bungling muddle of 

 our domestic ventilation. 



Let us suppose that we are going to open a coal-pit to 

 win the coal on a certain estate. We first ascertain the 

 " dip " of the seam, or its deviation from horizontality, and 

 then start at the loivest part, not, as some suppose, 

 at that part nearest to the surface. The reason for this 

 is obvious on a little reflection, for if we began at the 

 shallowest part of an ordinary water-bearing stratum we 

 should have to drive down under water, but, by beginning 

 at the lowest part and driving upwai-ds, we can at once 

 form a " sumpf," or bottom receptacle, to receive the 

 drainage, and from which the accumulated water may 

 be pumped. This, however, is only by the way, and not 

 directly connected with our main sulyect, the ventilation. 



In order to secure this, the modern practice is to sink 

 two pits, " a pair " as they are called, side by side, at any- 

 convenient distance from each other. If they are deep, it 

 becomes necessary to commence ventilation of the mere 

 shafts themselves in the course of sinking. This is done 

 by driving an air-way — a horizontal tunnel from one to 

 the other, and then establishing an -'upcast" in one of 

 them by simply lighting a fire there. This destroys the 

 balance between the two communicating columns of air ; 

 the cooler column in the shaft without a fire, being heavier, 

 falls against the lighter column, and pushes it up just as 

 the air is pushed up one leg of an (J tube when we pour 

 water down the other. Even in this preliminary work, if 

 the pits are so deep that more than one air-way is driven, 

 it is necessary to stop the upper ways and leave only the 

 lowest open, in order that the ventilation shall not take a 

 short and useless cut, as it does up our fire-place openings. 

 Let us now suppose that the pair of pits are sunk down 

 to the seam, with a further extension below to form the 

 water sumpf. There are two chief modes of working a 

 coal-seam, the "pillar and stall" and the "long wall," or 



