166 
NATURE 
[OcToBER 9, 1913 
sources of information, the statement of the results 
for all countries, details as to the method of investiga- 
tion, and so on, but the condensed tabular summary 
which follows is typical of the results as a whole :— 
— | Wheat Oats Barley Potatoes 
| | 
| (a) (4) | (€) || (a) || (2) | (4) | ©) || @| @) © 
, ft | 1'4| 3°4) 2°4]| 4°2] 6'9) 1°6 5'0) 9°4| 1°9]| 5°3| 6°8) 1°3 
United Kingdom) 2. | 1’0! 2°3) 2°4|| 3°9| 6’0, 1'6) 3°9, 7.3) 19) 4°0) 479) 12 
Ns: 0°7| 1°7| 2°4/| 3°4| 5°0| 1°5 aie} 4°7| 1°8)) 574] 4°5| 13 
SS ele SS SS SS 
be g’0/13°2| 1°5|| B'g}10°2) 1°1) -5"0 6’0) 1°2}/13°5]15 6) .x°x 
France =... »..42. | 8°1 118) r’5|| 8°7].8°3! 1’0|/° 3 ‘9. 4°5) °2||117t|1074]-0'9 
\. 167 9°8) 1'5|| 7°6| 7°9| 1’o|| 2°s| 29] 1°2||10°5| 8°6| o°9 
| | 
—||— |— | |, — —|— || | — | — 
{ ! | 
tr. |15'7|t0'7| 0°7|134°3|22°0 0°6) 25°8 1673] 0°6||14°2| 8°3/ 06 
Russia 2. |17°2|21°6) 0°7}|33°0|22"4| 0°7| 30°9 210} 0°7||24°6]16"4| 077 
3 }19°6 14 3 0°7]/32°3|22°8) 0'7| snoian7 0°7||28°0|19 7| 0°7 
| | 
yi ate Kin inenal emit eee | bares) ree ne 
I. |19°3)18°7| x°o||22"6)24°8| r| 6 7/0] 1°3]|"9°2], 5*0) 0'5 
United States ...)2. |20°5/21°6) 1°0||24'0/2°*7) 10] 5°5| 6°8| 1°2!| 8°9] 4°7] 05 
“* (5. |19°6)20°4) 1°0||24*1/2571 all 8*r 10°3) 1°3]| 8'9] 5°5| 06 
| | 
ert ee evil Sack ie | ire TS] eel ee 
| (x) | (2) | (3) |] G) | @) GF) |} @) |G) |) D}@] G@) 
weed ae si 100] 103| 113]] 100 sig | 100 106] 115]| 1co] 108) 114 
Decades—(1)= 1881-1890, (2) =1891-1900. * (3) =1901-1910. 
(a) Percentage of world’s acreage. (4) Percentage ot world’s crop. 
(c) Ratio of (4) to (@)=relative productivity per acre. 
Column (a) gives the average percentage acreage 
for the three last decades, and column (b) the average 
percentage total crop; France is typical of the 
countries which have declined, and Russia of. those 
which have improved under these heads. Column (c) 
measures relative productivity, which has been prac- 
tically constant all the world over for the three 
decades. Information is added to show the increases 
which: have taken place for the world as a whole in 
relative yield per acre. 
The end of the nineteenth century may be con- 
sidered as the close of a commercial revolution due to 
improved communications and transport, &c., and 
therefore the period under review is notably distinct 
from earlier epochs, so that the relative constancy 
of the productivity of these and other crops may be 
held to be a characteristic of this revolutionary period. 
Farming is a world business; improved results are 
common to all countries. The figures are -instruc- 
tive with reference to the threat of a world famine, 
e.g. if Russia only improved to the level of the 
United “States, there would be an increase of 6 per 
cent. in the world’s crop of wheat.’ At the ‘same time 
it becomes obvious that the British farmer. is the 
most ‘successful farmer in the world; he always 
obtains a higher: yield for each acre of land he tills. 
These are but the most important conclusions to 
which these results point; others may suggest them- 
selves to your readers. B. C. WaALLIs. 
Granville Road, North Finchley, N. 
The Elephant Trench at Dewlish—Was it Dug? 
I was not aware that it had occurred to Mr. 
Clement Reid, before it had done so to me, whether the 
Elephant Trench might have been excavated by man. 
He does not refer to this in his survey memoir on 
the Dorchester district; and so far as I can recollect 
he did not.mention it when I described the trench 
with lantern slides at the meeting of the British 
Association at Cambridge in 1904. He now states 
NO. 2293, VOL. 92] 
| (NatuRE, Sept. 25) that he is convinced that the 
trench was due to natural agencies, and suggests that 
it was ‘‘probably wind-cut by the swirl of the fine 
dust-like quartz sand which, ‘mixed with polished 
flints, now fills the lower part.” 
For my part I cannot imagine how such a trench 
could have been formed in that manner. He says 
that he found the sides of the trench ‘curiously 
smooth, and no tool marks nor rubbings such as 
might be made by man working in the trench, or 
by wild beasts,” and also that the flint nodules 
projected into the cavity from either side as though 
the softer chalk had been scoured away. The fine 
sand which partially fills the trench is, I think, to 
all appearances wind-borne; and during the long 
interval which probably elapsed before the trench had 
become filled up -by natural agencies the surface of 
its walls would) have become weathered away, and, 
possibly abraded by the sand, leaving the courses of 
flints projecting, and completely obliterating any tool 
marks. 
Mr. Reid remarks: ‘If this sand-filled fissure is 
found to continue downwards, but is too narrow for 
a’man.to work in, it will show that the trench is not 
artificial." On the other hand, my late lamented 
friend the Rev. R. Ashington Bullen wrote to the 
Geological Magazine (July, 1910, p. 334), describing a 
pitfall to catch antelopes. It was 1o ft. deep, 2 ft. 
wide at the top, narrowing at the bottom to a few 
inches. 
I may, however, say that when I dug at the end 
of the trench on the hill-face I came to the con- 
clusion that the bottom of the trench was a flat chalk 
surface, and near the bottom I found some angular 
coarse gravel, and among it a nearly worn-down 
molar along with the polished flints. If, as Mr. Reid 
suggests, the trench was excavated by wind, which 
appears to me impossible, all the flints corresponding 
to the chalk so removed ought to lie, now, unbroken 
at the bottom, but in my notebook I find the remark 
that the flints in this gravel did not appear to have 
come ‘‘from. the chalk direct.” 
I am extremely glad that Mr. Reid’s interesting 
reply to my letter shows that I have succeeded in 
directing the attention of geologists to this, as I 
believe, important question. 
O. FisHER. 
Graveley, Huntingdon, September 26. 
REFERRING to Mr. Clement Reid’s letter on the 
origin of the Elephant Trench at Dewlish, in NaTuRE 
of September 25, on the Yorkshire wolds holes are 
not infrequently- scooped out of the chalk by what 
are locally termed ‘‘cloudbursts.’’ One such, 13 ft. 
deep, occurred in the parish of South Cave last year. 
: G. W. B. Macrurk. 
15 Bowlalley Lane, Hull, October 4. 
A New Poet of Nature. 
Reapers of The English Review must be inured to 
shocks; but among the revolutionary visions which 
its young men have seen, surely nothing more 
startling has been recorded than this, which I extract 
from a short poem entitled ‘‘ Early One Morning" :— 
‘““ Have you heard what the young moon said to me 
As I walked in the morning early? 
She lay on her back and laughed at me 
As I walked in the morning early.” 
W. D. E. 
