258 REPORT— 1887. 



likely to become general. The zone of observation most suitable to our 

 purpose would probably be as it were the coast-line of trade, those articles 

 of world-commerce which are most sensitive to changes propagated from 

 abroad. In taking such a mean of observations the ' weights ' are not 

 necessai'ily proportioned to the masses of commodity. Frimd facie and 

 in the abstract pepper may afford as good an index as cotton. (See 

 pp. 281, 282.) The writer has given rules for taking the mean of these 

 observations. But he is aware how difficult it is to define the proper 

 zones ; how hardly susceptible of perfection is the science of monetary 

 meteorology. 



Contemplating all these types we discern a property common to most 

 of them, the desirability of treating separately selected interests, rather 

 than operating upon all commodities indiscriminately. To construct such 

 partial measures does not seem to be the business of this Committee, or 

 at least this Memorandum. We may, however, hope that our theoretical 

 diagnosis of different purposes may be of use to those who undertake the 

 more practical task of prescribing for different interests. 



Section I. 

 Description and Division of the Problem. 



The business of this Committee is to measure a fact, not to speculate 

 about its causes or consequences. Should a fall in the value of money 

 have occurred we need not trace that phenomenon to its sources. Whether 

 it takes its rise on the side of the precious metals or of commodities — ■ 

 whether, in Dr. Johnson's phrase, it is the pence that are few or the eggs 

 that are many — it is not our part to determine. The consequences of the 

 change are equally outside our province. It is open to us to hold with 

 Hume that, when prices are rising owing to the influx of money, ' every- 

 thing takes a new face ; labour and industry gain life.' With General 

 Walker we may predicate the converse attributes of falling prices. Or we 

 may accept Professor Marshall's ' qualified, or Mill's ^ negative, statement 

 of those effects. We have to leave speculation and apply ourselves to 

 measurement. 



But, while we are not called upon to decide such controverted ques- 

 tions, we cannot be as indifferent to the decision as might at first sight 

 have appeared. For it is only in the simpler kinds of measurement that 

 the metretic art can be entirely divorced from theory about its subject- 

 matter. To measure the height of a man we do not require a knowledge 

 of anthropology. We may even ascertain the mean stature of a nation 

 without much special knowledge. But difiiculties arise when we have to 

 do not with one attribute, such as height, but with two (or more) attri- 

 butes : for instance, the masses and velocities of a system of bodies. 

 Take the simple case of a number of heavy particles at rest, and suppose 

 that different velocities are imparted to the different particles between 

 two given epochs. It would not be very easy for one coming fresh to the 

 study of mechanics so to define his confused general idea of the change of 

 motion which had occurred as to be able to express it in terms of the data : 

 namely, the masses, say M,, M2, &c., M,„ and the imparted velocities 

 (which, in order to minimise difficulties, we will suppose all in the same 

 direction) V,, Vj, &c., V,,. It is plausible to say that the problem is 



' Third Report on Industrial Depression, Appendix C, vol. ii. p. 422, column b. 

 * Pol. Econ. Book III. chap. xiii. s. 4. 



