392 ACTUAL WORKING IN ORIGINAL RESEARCH. 



quantitative relations, we should in all cases of original 

 research make' measurements of the phenomena, and all 

 their attendant -conditions and circumstances, whenever 

 practicable, and especially of the most important ones. 

 As the phenomena to be measured are often very minute, 

 and their magnitudes cannot be estimated by means of 

 our senses, and as the instruments we employ to measure 

 them always admit of some interferences and some degree 

 of inaccuracy, it is of great importance, in nearly every - 

 case, to employ the most trustworthy and accurate instru- 

 ments. Every new refinement in our methods and instru- 

 ments of measurement is sooner or later employed for 

 making additional discoveries. Instruments of precision 

 have immensely aided discovery, and every investigator 

 should therefore possess those adapted to his researches 

 such as accurate goniometers, barometers, balances, micro- 

 scopes, spectroscopes, photometers, thermometers, elec- 

 trometers, galvanometers, &c. Accurate measurement is 

 also very important for the purpose of making units, 

 standards, rules, measures, verniers, zero-points, maxi- 

 mums, minimums, speed-ratios, &c. &c. ; and the use of 

 such accurate units, standards, &c., is also of very great 

 value. Less accurate instruments or measurements cannot 

 be employed to verify the truthfulness of more accurate 

 ones ; it is of but little use to measure an effect unless we 

 also measure its cause and conditions, nor to measure the 

 cause or conditions unless we also measure the effect, nor 

 to measure the one much more accurately than the other. 

 Tables of terrestrial constants, obtained by daily measure- 

 ment and record of the phenomena of light, heat, mag- 

 netism, and electricity, all over this globe, are also of 

 immense value in leading to discoveries respecting this 

 planet and other heavenly bodies, and their true functions 

 in the universe. 



