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SCIEJSrCE, 



[Vol. VllL, No. 17» 



we can say in reply is, that this arises either from 

 misapprehending what a science is, or from con- 

 temning the subject as unworthy of study. Science 

 consists very largely in the establishment of exact 

 relations between cause and effect, and a sub- 

 ject in which such a relation cannot be traced is 

 unworthy of serious study as a science. In a 

 word, if we admit that we can trace the relation 

 of cause and effect, then we admit ourselves to be 

 dealing with a science. If we do not admit this, 

 then it is of no use to talk about questions of eco- 

 nomic policy, and the safest course is to frown 

 upon all social movements as productive of results 

 which no man can foresee, and which are as likely 

 to do harm as good. 



The next question which arises is, how shall we 

 proceed to acquire the necessary knowledge of 

 society, — by purely deductive processes from 

 general principles, or by the study of the facts as 

 developed by history and statistics ? I reply, we 

 can attain no result except by a judicious combi- 

 nation of both processes. Some questions can be 

 settled conclusively by common-sense deduction, 

 while others are about matters of fact, and can be 

 settled only by a study of facts. If a proposition 

 were before the people of New York to withdraw 

 water fronl the Croton Lake for industrial uses, 

 and if the promoters of the scheme should publish 

 an historical investigation of the phenomena of all 

 aqueducts from the time of Caesar until now, to 

 show that the withdrawal of the water would in- 

 crease the available supply in New York, every- 

 body would laugh at them. So in economics. No 

 study of facts will tell us whether the number of 

 houses available for a community will be increased 

 or diminished by restricting the number of men 

 who shall be allo\ved to learn the arts of carpentry 

 and brick-laying, and by diminishing their hours 

 of labor. But common sense settles the question 

 at once. 



If asked whether the most urgent want of the 

 student is a knowledge of facts, or the practice of 

 deduction and the study of deductive methods, I 

 should reply that neither was urgent. What is 

 really urgent is, that he shall know how to study 

 facts effectively, and be able to understand prin- 

 ciples rationally. The prevailing defect of the 

 times is too much reliance on deduction, and too 

 little understanding how to study the facts of the 

 social organism, and how to apply principles to 

 the study. What all economists should agree 

 upon in their teaching, is to emphasize both the 

 understanding of j)rinciples and the investigation 

 of facts. 



I have in my mind's eye cwo ideal men. The 

 one has at his fingers' ends the state of commerce 

 and trade the world over, kAovvs the amount of 



imports and exports of all nations, and has their 

 laws of banking and currency learned off by heart, 

 but, with all this knowledge, does not understand 

 the laws of supply and demand, nor see any reason 

 why there should be a relation between the im- 

 ports and exports of a country. The other ideal 

 man has a clear understanding of the laws of sup- 

 ply and demand, and all other abstract principles 

 of economics, but is absolutely ignorant of the 

 actual condition of trade and commerce in any 

 part of the world. Which man is better equipped 

 to answer an economic question ? I reply, that, 

 taking them as they stand, neither is well equipped. 

 But the second man has this advantage over the 

 first, — that, when the question is presented to him, 

 he will know how to investigate it, and, with the 

 aid of better informed men, will be able to find 

 out the essential facts for himself ; while the other 

 man will never be able to make any really valuable 

 use of his knowledge. Hence I prefer a system 

 of instruction which is more concerned in teach- 

 ing the student how to think and investigate, 

 than in storing his mind with facts. 



Simon Newcomb. 



GEOGRAPHICAL NOTES. 

 The Kongo. — The steam-launch Peace, belong- 

 ing to the English missionaries on the Kongo, has 

 been busily engaged, since her arrival on the river, 

 in geographical work. Among the voyages made 

 and reported by the Rev. G. Grenfell are a recon- 

 naissance of the Kassai or Quango to longitude 

 17° BO' East Gi'eenwich. Another journey in- 

 cluded a visit to the Lomami and Ikelemba, 

 affluents of the left bank, and several others of 

 the right bank, among them the Nkemfe, which 

 proved narrow and tortuous. The Mobangi was 

 navigable as far as explored ; the Itimbiri also as 

 far as the Lobi Falls, in 23*^ 28' east longitude and 

 1° 50' north latitude. At three or four miles 

 from the junction of the Mbura with the Kongo, 

 the former was found to divide into two branches, 

 both barred by rapids or falls, the south branch 

 having a cataract forty feet high. The Lomami 

 is a fine river ; but the current is very swift and 

 the channel tortuous, so that the launch could 

 make good but some six miles a day during the 

 latter part of their stay upon it. In August of 

 last year the Lulongo was ascended to a distance 

 of nearly seven hundred miles. Its principal 

 affluent is the Lopori, in 1° 12' north latitude. 

 Stanley's Black River, which enters the Kongo 

 near the equator, is formed by the junction of the 

 Juapa and Bosira. Hostile tribes forced the 

 explorers to retreat after exploring the former 

 some three hundred miles, when it was still 

 navigable. The Bosira was only navigable for 



