March 6, ISso.J 



KNOWLEDGE 



185 



V AN ILLUSTRATED V> 



MAGAZINE OF SCIENCE 



NLYWORDED -EXACTLY DESCRIBED 



LONDOX: FRIDAY, MARCH G, 1S85. 



Contexts of Is'o. 175. 



The Falls of Ni«g»r«. By Eichird A. 



Proot.<r IS3 



The Phvlosophj of Clothing. III. 



By W. M«tti»a Willunns 186 



Future Arctic Work. II. By Lieut. 



GraeW 187 



Zodi«.l M«p. By R, A. Proctor .. l-' 

 Forms of Leavea. II. By Sir .John 



Lubbock l-*' 



Pleesmnt Uourswith the Microscope. 



(i«i.j.) Bt H. J. Slack 1!*1 



Tricycles in 1835. By J. Browning... 1!H 

 The Toune Electrician. (lUut.) 



ByW. Slingo 192 



rioi 

 Our Two Brains. By Richard A. 



Proctor 193 



The Forthcoming; Photographic Kx- 



bibition l'2\ 



Chapters on Modem Domestic Eco- 

 nomy. {Iltxis.) XVII 193 



Ttif Inter-Oceanic Ship Railway. 



/:<..) 196 



Oih.-r Worlds than Ours 1H9 



Editorial Gossip 200 



Reviews 201 



Correspondence 202 



Our Inventors* Column 203 



Our Chess Column 206 



THE FALLS OF NIAGAEA. 



By Richard A. Proctoe. 



I WRITE these lines in view of the Falls of Niagara. 

 The very room in which I am writing, though the 

 walls of the house to which it belongs are of more than 

 the usual s-trength, vibrates like the cabin of an ocean 

 steamer. The roar of the mighty Horseshoe Cataract, com- 

 bined with the more distant but distinguishable tones of the 

 American Cataract, fills the air with resounding evidence 

 of the might of gravity. That is with me the special 

 influence of this stupendous natural phenomenon. It seems 

 to speak to me of the energy of that force which alone, of 

 all the forces known to man, seems to bo the constant, 

 ever-present attribute of every particle of matter. When 

 I first saw Niagara from a great distance, the idea of 

 solemn calm, which Dickens found most impressive even 

 when close to the great cataract, forced itself on me as 

 the chief and overruling idea suggested by the contempla- 

 tion of the imposing spectacle presented here. Even then, 

 however, the sense of constant increasing energy as.sociated 

 itself with the sense of calm and almost of rest. If two 

 ideas so incongruous as rest and work can ever fill the 

 mind simultaneously, it is when, as at Niagara, we see a 

 force at work unceasingly. Re.stfully, though unrestingly 

 — restfully, because so easily and steadfastly — the great 

 cataract does its work. The consciousness that for 

 thousands of years the same processes have been at work, 

 cutting their way through the strata of the raised land 

 separating Eiie from Ontario, the thought that for 

 thousands of jears the work will continue, till at last the 

 waters of Erie will find vent in a tremendous cataclysm 

 by which the whole face of the region between Erie and 

 Ontario will be altered, is suggestive of power so immense 

 that its exercise year by year, day by day, minute by 

 minute, seems, when compared with its totality, like rest 

 rather than like work. 



But close by the ever-rushing masses of water, especially 

 by the shores of the upper or of the Lower Rtpids, one 

 cannot escape the sense of energetic action — at least, I 

 cannot, for my own part. The feeling comes on me that 

 here one sees gravity at its work. Here is the mighty 



terrestrial eneigy which yet is but a sample on an e.^- 

 ceediunly small scale of the energy which operates 

 throughout all space, on suns as on planets, on systems of 

 suns as on solar systems, on systems of such galaxies, and 

 on higher and higher orders of systems absolutely without 

 end. We recognise terrestrial gravity at its work here, 

 however, only becau.so it has hei(! work to do on such a 

 scale as to atl'ord some idea of the real meaning of gravity, 

 and yet within such compass tiiat we can grasp the sense 

 of the work that gravity is doing. And it is because, vast 

 though the work is in one Ecnsc, it is so exceedingly minute 

 in another, that the scene piesented by Niagara is so 

 impressive when rightly understood. 1 lere gravity works 

 on just so much of tlii^ waters of the great lake system 

 between Jiritish Noith Anieiica and the United Stutes as 

 corresponds with tiie rainfall on the area whose drainage 

 reaches Lakes Supeiior Michigan, Huion, and Erie. 

 The supply is intermittent, the outflow almost uniform. 

 Very slight is the diifeience which a wet or a dry season 

 makes in the wateis of Niagara. But to think that the 

 rainfall cf this area, a downtall which seems locally insig- 

 nificant, is here concentrattd into tuch mighty musses of 

 water ! and, still more, to think that the gently-acting 

 forces by which the waters of the sea are rai.sed into the 

 air in the form of cloud, and falling thence as rain (in 

 which a portion of their energy of position is ])arted with), 

 are here represented by forces acting wilh such resistless 

 energy, such constant noise and turmoil ! To the mere 

 accident (in a sense) that the water raised from the seas 

 has here fallen on upraised regions instead of on the lower 

 levels, to the mere diflfereuce of height between the places 

 on which they fall and the sta level from which the sun's 

 heat raised them, we owe the tremendous forces represented 

 by the Falls of Niagara and the Upper and Lower Ea])ids 

 of this short but most active river. Nay, we may go further, 

 and yet be far within the limits of Niagara's wonders. 

 The clouds which float in the air over Noith America 

 contain within them potential energies enormously exceed- 

 ing all the forces at work here in Niagara, for they repre- 

 sent not alone the drainage of the Great Lake Valley, but 

 of the whole area drained by the Missouri, the Mississippi, 

 and the other mighty rivers of the continent. A small 

 portion of these energies, finding its way along the Lake 

 Valley to Niagara, is concentrated into the tremendous 

 exhibition of force which is so impre.^-sive — nay, so appal 

 ling — to all who stay long enough near Niagara to apprehend 

 rightly its significance. 



Here, then, we have Niagara telling us of terrestrial 

 gravity, not only by appealing to our senses of sight and 

 sound in such sort as to overwhelm and confound ua by its 

 gathered energies, but also by appealing to our reason so 

 as to assure us that " these are but a porti(m " cf the great 

 force of gravity ; " they utter but a whisper of its might, 

 the thunder of its power who can understand 1 " If, in 

 drawing but a most minute fraction of the earth's rainfall, 

 through a few hundred feet (the Falls themselves are but 

 IGO feet in height) the earth's gravity can present such 

 impressive evidence of its might, what must we think of 

 the whole energy even of terrestrial gravity 1 And terres- 

 trial gravity is less than the 300th part of Jupiter's gravity, 

 less than the .jOO,OOOth pai t of the sun's gravity, while 

 even the stupendous force of solar gravity is dwarfed 

 almost into nothingness by comparison with the attractive 

 mi'dit of SiriuR, Vega, Altair, and others of that chief 

 order of stars whose bluish white light tr-lls us of vastly 

 superior mass, and, presumably, of relative youth, from 

 what we know of the laws according to which greater and 

 lebs masses have longer and shorter stages of cooling — that 

 is, of life. Absolutely as nothing, in turn, is even the 



