May 31, 1889.] 



SCIENCE. 



429 



These conditions, brought about by action during the glacial pe- 

 riod, are among those which, in Dr. Dawson's opinion, have most 

 tended heretofore to retard the development of metalliferous mining 

 in British Columbia. Other circumstances which have operated in 

 the same direction are, the densely wooded character of a great 

 part of the country ; the fact that the rivers are suited for naviga- 

 tion only in detached reaches ; the remoteness from the coast of 

 the richest and best-known placer-mining districts ; and the cost 

 of labor, supplies, and machinery, which may be regarded as in 

 part concomitants, in part direct results, of these. Owing to the 

 inaccessibility of the country, it has, till very recently, been pros- 

 pected and exploited by the placer-miner alone, who has been de- 

 terred by no difficulty from reaching the most remote spots in which 

 rumor, or reasoning of his own, lead him to e.\pect the existence of 

 the precious metal. Little knowledge or effort was expended in 

 the search for metalliferous veins. Many such deposits supposed 

 to be of value, were, it is true, located, and time and money which 

 could ill be spared often uselessly spent upon them, leading only to 

 discouragement. Even where the indications met with were alto- 

 gether favorable, the original discoverer generally found that the 

 capital and knowledge required for their development were not at 

 his command, and it was difficult to interest those capable of deal- 

 ing with such mines in a region which they could not easily visit 

 and become familiar with at first-hand. With regard at least to 

 the whole southern portion of the province, however, all this is now 

 happily changed. 



While speaking of causes which have hitherto stood in the way 

 of vein-mining, it must also be mentioned that not the least impor- 

 tant of these has been, and still is, the fictitious or exaggerated 

 value too frequently placed upon entu'ely undeveloped discoveries. 

 While it is manifestly right that the discoverer should be properly 

 remunerated, it should be remembered that a mere surface show- 

 ing, however promising, generally requires the expenditure of a 

 large sum before its true value can even be ascertained, and that 

 till thus developed it is unreasonable to expect a large payment for 

 any mining claim. 



In preceding paragraphs particular attention has been drawn to 

 certain notable differences between the better-known and more 

 fully developed regions of the southern part of the Pacific slope and 

 those of the province of British Columbia, chiefly as a note of cau- 

 tion against the rash assumption of complete uniformity in condi- 

 tions too often made without due investigation. The salient fact 

 of the general identity of the structural features of the Cordillera 

 region south and north, however, remain, and is such, that from 

 this alone, even without taking into consideration the numerous 

 and important discoveries already made, we should be justified in 

 predicting an eventual great development of metalliferous mining 

 in the province. It has already been stated that British Columbia 

 includes a length of over 800 miles of the most important metal- 

 liferous belt of the continent ; and, adding to this the northern 

 extension of the same belt beyond the 60th parallel, we find that 

 within the boundaries of Canada its entire length is between 1,200 

 and 1,300 miles. This, as has elsewhere been noted, is almost 

 precisely equal to the whole length of the same region included by 

 the United States from the southern line of Canada to the northern 

 boundary of Mexico ; and Dr. Dawson, after having enjoyed excep- 

 tional opportunities of investigation, feels no hesitation in recording 

 his belief that the northern moiety of the Cordillera will ultimately 

 prove to be susceptible of a development corresponding in impor- 

 tance to that which has already been attained in the southern. 



British Columbia first rose from the position of a fur country to 

 the rank of a colony, on the discovery of gold upon the Lower 

 Fraser in 185S. Its subsequent history for a number of years is 

 substantially that of the sudden rise and subsequent slow decline in 

 importance of placer gold-mining. Coal-mining has, however, 

 concurrently advanced, slowly but steadily, till it has obtained its 

 present pre-eminent position. Such historical facts as appear to 

 be important to the appreciation of these industries are touched 

 on later in connection with them. With respect to vein-mining 

 proper, we have as yet to chronicle merely the first steps ; but in 

 the southern part of the province the completion of the Canadian 

 Pacific Railway has at length afforded the necessary impetus in 

 this direction, and it is very gratifying to find, as an immediate 



consequence, that this part of the- country is rapidly beginning to 

 prove its valuable character, and to justify the confidence which 

 those best able to form an opinion on the subject have always felt 

 and frequently expressed. Every thing which has been ascertained 

 of the geological character of the province as a whole, tends to the 

 belief, that, so soon as similar means of travel and transport shall 

 be extended to what are still more inaccessible districts, these also 

 will be discovered to be equally rich in minerals, particularly in the 

 precious metals, gold and silver. In the southern district, for 

 which information is most complete, praiseworthy efforts are now ■ 

 in progress, at a number of widely separated localities, toward the 

 exploitation of ores, which, in many cases, have already been 

 proved to be of an exceptionally valuable character. Here, at least, 

 there is every reason to believe that we are on the point of wit- 

 nessing the inauguration of an era of mining activity of the most 

 important kind. 



AMONG THE PUBLISHERS. 



The Jottrnal of Morphology for June, being the first number 

 of Vol. III. (Boston, Ginn), contains the following articles, besides 

 eight lithographic plates : " The Actiniaria of the Bahamas," by Play- 

 fair McMurrich ; " Contributions to the Osteology of the North Amer- 

 ican Passeres," " Notes on the Anatomy of Speotyto," by R. W. Shu- 

 feldt ; " Variation of the Spinal Nerves in the Caudal Region of the 

 Domestic Pigeon," by James I. Peck. The second number, that for 

 August, will contain " The Mechanical Origin of the Structures of 

 the Hard Parts of the Mammalia," by E. D. Cope; "The Embry- 

 ology of Blatta and Doryphora," by William M. Wheeler ; besides 

 numerous cuts and seven lithographic plates. For the third 

 number, the "Embryology of Linnbricus," by E. B. Wilson, is 

 promised, and a paper by William Patten, dealing with the general 

 embryology, including the segmental sense-organs, of arthropods. 

 This number will probably be issued in October. A fourth number 

 will probably be given with this volume, but its contents cannot be 

 definitely stated. The subscription price is nine dollars for the 

 volume, whether including three numbers or four. 



— We have just received the first part of Vol. I. of the new 

 " Century Dictionary," published by The Century Company, New 

 York. This number appears in a unique and attractive binding,, 

 embracing the letters from A to Appet, and will be a welcome ad- 

 dition to the library. The work will be completed in six volumes 

 of four parts each. 



LETTERS TO THE EDITOR. 

 Fog. 



A GREAT deal of discussion has recently taken place on the 

 properties of fog and its causes. One writer attributes the cele- 

 brated London fog to the cooling of the air by radiation from hill- 

 sides near the city, which air, flowing down, envelops the city. It 

 has also been suggested that a cool northerly wind on the west 

 side of a storm flows into the saturated air on the south side, and 

 condenses fog. Again, over Newfoundland it is thought that a 

 saturated current flows from the southward to cooler waters, often 

 having ice floating in them, and thus produces fog. The objection 

 to the first theory is, that the cause assigned could not develop a 

 fog 500 or 1,000 feet thick. In the second case it seems plain that 

 the cool north wind is always dry, and would quickly render the air 

 unsaturated. In the last case, while the cause assigned might pro- 

 duce a fog just at sea-level, yet this would hardly be extensive 

 enough, and it is probable that a calm^is essential in fog-produc- 

 tion. 



Fog, it is admitted, is simply cloud composed of water- dust or 

 solid minute spheres of water from -^j^ to x(j,nj of an inch in diam- 

 eter. It is supposed by some that a dust-particle must be a nu- 

 cleus for each sphere. When we consider the billions of such 

 spheres in a cubic inch of fog, we may well halt, and demand that 

 the moisture in a few cubic feet of fog be evaporated, and the tril- 

 lions of dust-particles massed under a microscope, where they cer- 

 tainly ought to be visible. The laboratory experiments advanced 

 to prove this theory seem entirely inadequate, when we consider 

 the extreme improbability of such an hypothesis. 



