May 17, 1895.] 



SCIENCE. 



537 



■period i seconds or quarter period 1 second 

 we have the following values of a : — 



« = 1 10/6 2 



d I 0' — 0.632 0.774 0.810 



The middle one of these values corre- 

 sponds to the ring discussed above when the 

 resistance is one ohm. In these three 

 cases the maximum deflection is reached 

 after 1.54 seconds, 1.45 seconds and 1.40 

 seconds from the time when the e. m. f. is 

 applied to or removed from the circuit . The 

 conditions here taken may be considered ex- 

 treme in so far as the period of the needle 

 is concerned, but it is not difficult to find 

 examples of actual measurements in which 

 the period has been equallj' short. 



The examples here given are probably suf- 

 ficient to direct attention to the care that 

 must be taken in the choice of apparatus 

 and the arrangements of circuits when the 

 ballistic galvanometer is used in magnetic 

 measurements. The method is only appli- 

 cable when a is so lai'ge that 6 and 6' are 

 practically equal to each other and this 

 condition is approximated to by making R 

 large and L as small as possible. Hence, 

 high 6. m. f. s. should be used with high non- 

 inductive resistance in the circuit and mag- 

 netic force should be secured with small 

 numbers of turns by using large currents. 

 It is well alwaj's when comparing charge 

 with discharge to keep the induction of the 

 circuit the same in both cases by means of 

 an apparatus which cuts out the batterj' and 

 at the same time keeps the circuit closed 

 through an equal resistance, instead of 

 breaking the circuit when the discharge is 

 measured. A check on the accuracy- of the 

 observations in any particular case may be 

 obtained by observing the successive ex- 

 treme deflection of the needle. If the first 

 deflection has the proper magnitude the 

 mean ordinate of the curves drawn through 

 the extreme deflections to opposite sides of 

 zero should be at all points zero. When 



the duration of the current is a large frac- 

 tion of the time of swing of the needle the 

 mean of the deflections to opposite sides 

 will lie for the first few swings on the same 

 side of zero as the initial deflection. 



Thomas Gray. 

 Rose Polytechnic Institute. 



THE SCIENTIFIC 5IETH0D AND MODERN IN- 

 TELLECTUAL LIFE. 

 SciEXCE, as a necessaiy term, is possibly 

 upon the verge of obsolescence. Within the 

 last half-century it has spread the mantle 

 of its meaning over almost every depart- 

 ment of thought until to-day knowledge 

 and science are perceived to Vie so nearly co- 

 extensive that the newer term might rightly 

 yield to the priority of the older. While 

 twenty-five j^ears ago one heard much about 

 science and the languages as rival claim- 

 ants for place in the college curriculum, 

 one now listens to the message of that use- 

 ful science, classical philology. Then the 

 polemic between science and religion seemed 

 earnest indeed ; now theologians and lay- 

 men are alike shocked when Mr. Benjamin 

 Kidd suggests that there can not be a sci- 

 ence of religion. Antithesis has softened 

 into synonj-m}'. It is not that the lion of 

 science has devoured the lambs of art, liter- 

 ature and philosophj- ; it is rather that sys- 

 tematists of opinions and beliefs have deter- 

 mined a generic unity where before variety 

 was supposed eternallj' to exist. Such con- 

 dition has arisen, it may be presumed, from 

 the prevalence at least among Western na- 

 tions of what has come to be denominated 

 the scientific method. This prevalence is 

 not yet universality. It does not yet extend 

 in full measure to every individual; nor does 

 it, perhaps, persistentlj' characterize the 

 intellectual life of any man at the present 

 time. The atavism of superstition must 

 somewhere mar the image and supei-scrip- 

 tion of one's intellectual inheritance. Nev- 

 ertheless, so widespread and so dominant 



