2 6 THE POPULAR SCIENCE MONTHLY. 



cessary limits of our knowledge derived therefrom. The study which 

 he ought to make of errors, instrumental and accidental, will be of 

 great value to him in other fields than this. 



As an illustration of the lack of this sort of training, I may be al- 

 lowed to mention a lecture to which I listened recently, delivered by 

 the chief engineer of one of the leading railroads in the country. The 

 subject was the " Great Pyramid," and in speaking of certain measure- 

 ments taken in the interior he declared the results, which were given 

 in feet, inches, and thousandths of an inch, to be absolutely accurate, 

 taking especial care to disclaim anything in the nature of an approxi- 

 mation. 



I need hardly explain that he was declaiming against the introduc- 

 tion and adoption of a system of metrology which has done and will 

 continue to do much to increase the simplicity and accuracy of all 

 measurements. 



I have said that this quantitative work should be of the best quality 

 possible. It is better for the laboratory to contain a few instruments 

 of real precision than a large number of inferior performance and ac- 

 curacy. It is not a matter of great importance upon which particular 

 department of physics a student shall spend his time and strength. 

 The underlying principles of this method of study are common to all, 

 and it is a matter of experience that when a student has successfully 

 accomplished a tolerably exhaustive investigation of one topic, in- 

 volving, it may be, but a single instrument with its accessories, he is 

 upon his feet for the remainder of the course. 



To sum up, the course of study in physics for the undergraduate 

 collegian, which I have tried to indicate, should include a sufficient 

 training in mathematics to enable him to apply his knowledge with 

 ease and facility to the more common physical problems ; a thorough 

 and exacting course of text-book and lecture-work, in which the appli- 

 cation of his mathematical knowledge would be made, and during 

 which all illustrative experiments necessary to a complete understand- 

 ing of the text should be exhibited by the instructor from the lecture- 

 table ; and, finally, this to be supplemented by a course in the labora- 

 tory in which more attention is paid to the quality than to the quan- 

 tity of work done ; during which every problem is discussed, as far as 

 possible, both mathematically and experimentally, and especial atten- 

 tion is given to the discussion of the results of experiment, and of the 

 more elementary portions of the theory of errors. 



Considering the work as thus divided into three parts, I am unable 

 to see which is the least essential. 



I desire to say a few words in regard to instruction in physics in 

 the school, about which we are, apparently, more remotely concerned. 

 Even greater reform is demanded in this direction than in the other. 

 Although there are numerous American text-books, I venture the re- 

 mark that none have properly combined, in their making, the experi- 



