36 



♦ KNOWLEDGE 



(Jdlv 11, 1884. 



anhydrite obtains to any large extent ; its conversion by 

 hydration into gypsum being accompanied by a sensible 

 increase in bulk. 



Of the mechanical action of rain-water upon the earth, 

 we cannot do more than allude briefly to its power as a 

 denuding and disintegrating agent. The formation of 

 rivers and lakes — and, indeed, the whole landscape scenery 

 ■of the world — ia largely determined by the action of water. 

 The rain that does not sink into the ground flows off in 

 channels which it grooves for itself down the sides of hills 

 to rivers, lakes, and the sea. In its passage over the rocks 

 the water of rivers acts both mechanically and chemically : 

 dt holds in suspension not only insoluble particles, but 

 dissolved matters, which vary with the c;haracter of the soil 

 it has traversed; it is augmented by springs which may 

 bring to it water which has accumulated from a distant and 

 distinct region ; it is crowded with diverse forms of plant 

 and animal life, and may be polluted by the sewage and 

 other offensive products, not only of densely-populated 

 districts, but even of isolated tenements. This is well 

 chown in the subjoined figure (Fig. 14), for the use of 

 which we are indebted to the courtesy of Mr. P. A. 

 Maignen, of Great Tower-street, E.G. 



r^ 



Fig. 14. — Excellent mountain stream, affording a supply to a 

 country-house, and at a lower point to a small village. Defective 

 drains and overflow from cesspools (shown by dotted lines) pol- 

 lating the stream. 



In continuation of our remarks, we shall trace the 

 history of a drop of water from other sources, with 

 special reference to the waters of the Thames and the 

 London water-supply. We trust that these notes will 

 enable our readers to form an adequate estimation of the 

 value of the practical appliances which we shall soon place 

 before them, as in pointing out the details of mechanism it 

 will be found necessary to refer constantly to what we 

 have here attempted to explain. 



CcRious Case of C.tusE .\xd Effect. — During a storm at Green- 

 ville, R.I., May 9, the lightning ran by the telephone wire to the 

 Windsor Mill, where there is no telephone, but the wire is discon- 

 nected just outside the building. The lightning was led by the wire 

 to the corner of the mule and weaving rooms, and entered the 

 building under the jet. It followed the water-pipe and set the 

 sprinklers going, and at the same time tired the stock iu tlie mules. 

 By this singular provision of an active extinguishing agent at the 

 moment the fire started, serious loss was prevented, as the fire was 

 soon drowned out. Many of the spindles in the mules lost their 

 temper, and some of the belts were burned, but the mill was saved. 

 — Scientific Americaii. 



-RfbieUiS. 



SOME BOOKS ON OUR TABLE. 



Freemasonry Traced from Prehistoric Times, Ac. By A 

 Master Mason. (London. 1884.) — We are just in this 

 tremendous difficulty with the tract whose title heads this 

 notice : its author is inspired ! At least he says he is — and 

 he ought to know. He traces Masonry from the Magi, 

 and suggests the establishment of a .Supreme Grand Lodge 

 and a Supreme Grand Chaplain of the whole world. He 

 further is good enough to inform us on the cover that " All 

 known substances are not only held together by electricity, 

 but all things, atoms included, are composfd entirely of 

 electricity." This is .Jachin and Boaz, Hiram and Tubal 

 Cain run mad with a vengeance. 



On ail Error in EUiplic Motion. By A Stukest. (Leeds: 

 Jobn Lennox. 1884.) — The "Student" regards the 

 Dynamics of Tait and Steele as radically unsound, has 

 mounted a piece of apparatus to illustrate elliptic motion, 

 and gives a sketch of a " Typical orbit. Diagiam obtained 

 by placing magnet beneath plane and niling sphere," among 

 other illustrations. None are so blind as those who wont 

 see. 



The Unlimited Debt. By F. W. D. Mitchell. (Dublin : 

 A. Thorn i Co., 1884.)— Mr. Mitchell is a disciple of Mr. 

 George's, and apparently — with Proudhon — regards pro- 

 perty (in the form of land) as iheft. He etsays — not very 

 succes.sfully — to answer the Duke of Argyll's article, "The 

 Prophet of San Francisco," in the April numl^er of the 

 Xiiti-te.inllt Century. One elementary fact is certain — 

 either land must remain in piivate hamls, or it must 

 become the property of the State. In the latter case rent 

 and taxation must become synonymous ; and then God help 

 the cultivator of the soil ! 



The Abuse of Blue Rihbonism. By a Moderate 

 Drixker. (London : Iliffe i Son.) — This is a temperate 

 protest again.st the rant but too often heard upon teetotal 

 platforms. Starting with the axiom that drunkenness is 

 both a curse and a sin, the author shows, alike from Scrip- 

 tural teaching and from the everyday experience of man- 

 kind, that the use of a strictly moderate amount of fer- 

 mented liquor is at once pleasant, harmless, and conducive 

 to health. 



The Slide-rule Extended. By Major-General Ha.v- 

 nysgtox. (London: E. i F. N. Spon. 1884) — By an 

 extension of the slide-rule. General Hanuyngton has pro- 

 duced an instrument which cannot fail to be of value to all 

 engaged in much logarithmic computation of the kind in- 

 volved in reducing astronomical observations, making 

 intricate divisions in a clearing-house, finding the cubic 

 contents of timber, and the like. His pamphlet explains 

 the principle of such extension, and illustrates the use of 

 the improved rule by examples. 



A Short Ex^position of Ma.-<snc/f, <tc. By G. FentON 

 Cajierox. (London: Bailliere, Tindall, i Cox.) — Massage 

 appears from this tract to be a kind of medical shampooing, 

 or rather kneading; and the tract itself may be looked 

 upon as a message to such as may need it. 



Hints on Sanitari/ Laira, dr. By G. F. Chambers, 

 F.RA.S. (London: Allman i Son. 1884.)— This short 

 digest of the numerous Acts of Parliament regulatii g the 

 sanitary condition of London is issued by the National 

 Health Society, and will be found useful by all interested 

 in the health of the metropolis. It gives a clear exposi- 

 tion of the law, and teaches the householder at once with 

 what sanitary requirements he must himself comply, and 

 how to enforce obedience to them on the part of his neigh- 



