KEDISTKIBUTION OF MANKIND DICKSOiS'. 555 



In the type of civilization with which we are most familiar there 

 are two fundamental elements — supplies of food energy and supplies 

 of mechanical energy. Since at present, partly because of geo- 

 graphical conditions, these do not necessarily (or even in general) 

 occur together, there is a third essential factor, the line of transport. 

 It may be of interest to glance, in the cursorj^ manner which is pos- 

 sible upon such occasions, at some geographical points concerning 

 each of these factors and to hazard some speculations as to the prob- 

 able course of events in the future. 



In his presidential address to the British Association at its meeting 

 at Bristol in 1898, Sir William Crookes gave some valuable estimates 

 of the world's supply of wheat, which, as he pointed out, is " the most 

 sustaining food grain of the great Caucasian race." Founding upon 

 these estimates, he made a forecast of the relations between the 

 probable rates of increase of supply and demand, and concluded that 

 " Should all the wheat-growing countries add to their [producing] 

 area to the utmost capacity, on the most careful calculation the yield 

 would give us only an addition of some 100,000,000 acres, supplying, 

 at the average world yield of 12.7 bushels to the acre, 1,270,000,000 

 bushels, just enough to supply the increase of population among 

 bread eaters till the year 1931." The president then added, " Thirty 

 years is but a day in the life of a nation. Those present who may 

 attend the meeting of the British Association 30 years hence will 

 judge how far my forecasts are justified." 



Half the allotted span has now elapsed, and it may be useful to 

 inquire how things are going. Fortunately, this can be easily done, 

 up to a certain point, at any rate, by reference to a paper published 

 recently by Dr. J. F. Unstead,^ in which comparisons are given for 

 the decades 1881-1890, 1891-1900, and 1901-1910. Dr. Unstead shows 

 that the total wheat harvest for the world may be estimated at 

 2,258,000,000 bushels for the first of these periods, 2,575,000,000 

 for the second, and 3,233,000,000 for the third, increases of 14 per 

 cent and 25 per cent, respectively. He points out that the increases 

 were due " mainly to an increased acreage," the areas being 

 192,000,000, 211,000,000, and 242,000,000 acres, but also " to some ex- 

 tent (about 8 per cent) to an increased average yield per acre, for 

 while in the first two periods this was 12 bushels, in the third period 

 it rose to 13 bushels per acre." 



If we take the period 1891-1900, as nearly corresponding to Sir 

 William Crookes's initial date, we find that the succeeding period 

 shows an increase of 658,000,000 bushels, or about half the estimated 

 increase required by 1931, and that attained chiefly by " increased 

 acreage." 



^ Geographical Journal, August and September, 1913. 



