]\Iay 12, I9IOJ 



NATURE 



13 



those of the coast. Here would be an unique chance. 

 At present the country is untouched, but in a dozen 

 j'ears it may well be opened up, and if gold be found 

 all would fall before the axe. 



Colonel Mackay's obser\'ations suggest much work, 

 too, for the ethnologist. The Yodda Goldfields have 

 brought to light red pottery with designs, and stone 

 bowls with patterns on their rims, indicating that 

 the country was once occupied by a race superior to 

 the present Papuans. The latter, too, even on the 

 coast, are interesting enough, but they are fast getting 

 spoilt by the missionaries and traders. Those of the 

 hills near " the gardens of the ghosts " are still un- 

 touched, making mummies of their dead, for whom 

 they have a supreme respect. The splay-footed people 

 near Cape Nelson should also be well worth a visit. 



It is rightly pointed out that no tropical countr)"^ 

 can remain long undeveloped, owing to the teeming 

 millions of the overcrowded E^st, and British New 

 Guinea, to be secure, must be opened up. Coco-nuts, 

 coffee, cocoa, and rubber will probably in a generation 

 cover most of the available land, while gold may 



Native Trading Vessels of Port Moresby. From "Across Papua." 



cause still more rapid growth. The book before us 

 will doubtless assist this development, as the condi- 

 tions and climate are shown to be by no means worse 

 than those of Ceylon or the Straits not many years 

 ago. Perhaps this is the aim of the book, but we 

 confess that we desire the more solid obser\'ations of 

 a trained naturalist. Unfortunateh', such have not 

 alwavs the brightness and sense of humour possessed 

 by Colonel Mackay. J. S. G. 



SOME RECENT AGRICULTURAL FIELD 

 TRIALS^ 



SINCE the application of the " whisky '* money to 

 agricultural education in Great Britain a con- 

 iiderable amount of experimental work has been car- 



1 West of Scotland Agricultural College, Reports on Experiments ; 

 Durham County Council Education Committee, Report of Dairy Investiga- 

 tions ; Northumberland Education Committee, Guide to Experiments for 

 1909 ; East Sussex Education Committee, Experiments on Meadow Hay ; 

 Ajgricultural Students' Gazette, Experiments on Pasture ; Journal of the 

 Department of Agriculture and Technical Instruction for Ireland. 



NO. 21 15, VOL. 83] 



ried on by sOme of the more energetic of the county 

 committees. A few of the experiments deal with 

 animals but by far the greater number with crops, 

 presumably because the expense is less; they serve a 

 variety of useful purposes, arousing an interest in 

 practical agriculture, showing the farmer (if, indeed, 

 he needs showing) that artificial manures will give 

 increases in crop, and, finally, they may furnish ver\' 

 useful material for the county agricultural lecturers. 



Field exp)eriments are perhaps the most difficult of 

 all experiments to interpret. The growth of plants is 

 influenced by so many factors— temperature, water 

 supply, food supply, &c. — that small variations in the 

 conditions may lead to marked differences in result. 

 The soil is a ver}' complex mixture and not uncom- 

 monly shows some variation even within the limits 

 of a single field. Even if the soil itself is tolerably 

 uniform a slope may introduce irregularities. The 

 influence of a tree or hedge makes itself felt for some 

 distance, while the effect of the previous treatment of 

 the ground is often ver\' great. Of course, if the 

 intention is mainly to get up an interest in agricul- 

 tural trials these con- 

 siderations are of little 

 moment, but they as- 

 sume great importance 

 where it is desired to 

 give definite informa- 

 tion about the effect of 

 manures on the crops. 

 A perusal of the reports 

 before us leaves a rather 

 mixed impression. 



There has been a vast 

 amount of work done, 

 and much industry and 

 energy have been dis- 

 played, but it is not 

 always clear that the ex- 

 perimenters have 

 grasped the first prin- 

 ciples of the art of mak- 

 ing experiments. In no 

 case is the experimental 

 error indicated, nor can 

 we find it has been as- 

 certained; indeed, so far 

 as we know, it is only 

 at Rothamsted that the 

 determination is made, 

 and there, where all the 

 conditions are favourable 

 and the workers tho- 

 roughly competent, i t 

 amounts to 10 per cent. 

 In the Sussex experiments a number of plots were 

 laid out on each of twent}' farms and received various 

 combinations of artificial manures. As the experi- 

 ments have only gone on for one year it is impos- 

 sible to draw any definite conclusion, so great is the 

 disturbing effect of season. In the discussion all the 

 results have been averaged, in spite of the fact that 

 the soil varied from a chalk loam in some -entres to 

 a heavy clay probably destitute of chalk in others. 

 It is, of course, not legitimate to take an average of 

 incomparable quantities, and we suggest that more 

 useful results would be obtained by arranging the 

 soils into strictly comparable groups. 



The Northumberland experiments have gone on for 

 a longer time and averages for several years are 

 given, so that the effect of season is more or less 

 eliminated. They are well known as illustrating the 

 value of basic slag in improving poor clay pastures. 

 On the light soils potash has l>een found verv effec- 

 tive. .\ more detailed studv could be made if the 



