July 14, 192 1] 



NATURE 



631 



to no complaints. A notice issued recently by the 

 Government of Malta announced that the metric 

 system was to come into force on July i. It has been 

 made obligatory in dealings with the Customs Depart- 

 ment as a preliminary to enforcing its use in general 

 trade in the island. The unsatisfactory manner in 

 ■which decimals are taught in the United Kingdom is 

 the subject of an instructive article in which it is 

 stated that, although teachers as a body are supporters 

 of the metric system, the accepted methods of teaching 

 arithmetic place the decimal fraction in an unfavour- 

 able light by giving unnecessary prominence to con- 

 version sums, and in this way seriously handicap 

 decimal reform. It is urged that so far as possible 

 all reference to vulgar fractions should be omitted from 

 the teaching of decimals, and that the examples neces- 

 sary to explain the meaning of decimals should be 

 drawn from the metric system and decimal coinage, 

 with an occasional sum involving such British 

 measures or coins as are connected by decimal rela- 

 tions. A useful chart Illustrates the progress made 

 in the adoption of the metric system during the last 

 "hundred years. The consistently upward trend of the 

 •curve and the particularly sharp rise during the past 

 ten years are noteworthy, and indicate that as each 

 new country joins in the competition of international 

 trade its national weights and measures are aban- 

 doned and the metric system adopted In preference. 



The National Institute of Agricultural Botany, 

 Avhich was organised with the object of improving 

 the seed supply in the United Kingdom, Is now 

 -making arrangements to conduct a comprehensive 

 series of yield and quality trials of wheat, oats, and 

 barley, to commence during the season 1921-22. The 

 trials will be carried out on a uniform and scientific 

 system In several parts of the country, and final re- 

 ^x>rts, on which the granting of certificates of merit 

 will be based, will be Issued after the harvest of 1924. 

 The trials will be open to all who can show that 

 they have in their exclusive possession new or im- 

 proved varieties or strains of any of these cereals, and 

 undertake to refrain from placing them on the 

 •market previous to the issuing of the final report on 

 their merits, except with the institute's consent. The 

 testing fee will be limited to the actual cost of the 

 trial. Fuir particulars of the scheme can be obtained 

 from the Secretary, National Institute of Agricultural 

 Botany, 10 Whitehall Place, London, S.W.i. 



Nos. 1-9 in vol. vi. (1920) of the Entomological 

 Series published by the Agricultural Research Insti- 

 tute, Pusa, are devoted to a series of papers on the 

 life-histories of Indian Microlepidoptera by Mr. T. B. 

 Fletcher. It is mainly within the last fifteen years that 

 any serious attempt has been made to acquire a know- 

 ledge of the species of the small moths which occur 

 in India. In 1889 only 225 had been enumerated, 

 while at the present time 2422 species contained in 

 about 458 genera are known. In spite of this large 

 number, Mr. Fletcher remarks that we are merely 

 beginning to learn what kinds exist in the Indian 

 Empire, where there are still enormous areas abso- 

 lutely unknown so far as Microlepidoptera are con- 

 cerned. In this series of papers a great deal of scat- 

 NO. 2698, VOL. 107] 



tered information Is brought together in a convenient 

 form, and short accounts are given of the life-histories 

 of a very large number of species. Many of the 

 latter, together with their larvae and pupae, are well 

 figured in a series of sixty-eight plates which accom- 

 panies the letterpress. 



Dr. Marjorie O'Connell (Bull, Amer. Museum 

 Nat. Hist., vol. xlli., p. 643, 1920) describes Jurassic 

 ammonites from Vifiales, western Cuba, which prove 

 the beds containing them to be of Oxfordian age. 

 The author points out that in a recent paper by Dr. 

 M. S. Roig previous descriptions of Mexican species 

 have become included as though they came from Cuba. 

 More may be expected, however, from Dr. Roig's 

 extensive collections, and Dr. O'Connell will, no doubt, 

 pursue her studies In this almost untouched field. 



In Bulletin 597 of the U.S. Geological Survey, with 

 Its large geological map on the scale of i : 250,000, 

 Mr. B. K. Emerson provides a handbook to "The 

 Geology of Massachusetts and Rhode Island," a region 

 associated with Boston Bay, one of the most famous 

 natural gateways of North America. Students at 

 Harvard and citizens of Providence In the drowned 

 valley of the Blackstone River, or of Pittsfield across 

 the picturesque and dissected uplands of Berkshire, 

 will welcome this record of the geological history of 

 their States. Fascinating reproductions of the early 

 Dinosaurs of Triassic times are given from models, 

 Including Stegomus, known from its armour only, 

 and the bipedal Anchlsaurus. The reader requires 

 geological training, but this should not be lacking 

 in the abundant secondary schools of Massachusetts. 



Special interest attaches to a recently published 

 Bulletin of the U.S. Geological Survey on "The Iron 

 and Associated Industries of Lorraine, the Sarre Dis- 

 trict, Luxemburg, and Belglurn," by Messrs. Alfred 

 H. Brooks and Morris F. La Croix. The bulletin 

 gives an exhaustive description of the position in 

 these districts and of their future possibilities, and is 

 full of valuable statistical information most care- 

 fully collected. At the moment the following passage, 

 written with reference to the Sarre coalfield, is per- 

 haps the most Interesting for British readers : — " It 

 has long been recognised in Germany that the Govern, 

 ment mines were less eflficiently operated than those 

 In private hands. Evidence of this difference Is found 

 in the reported cost of production. The average cost 

 per ton of coal mined in the years 1906 to 19 10 was 

 11.54 francs for the private mines and 13.50 francs 

 for the Government mines. This ratio of cost appears 

 to have continued for 1913, when the average profit, 

 as reported, was 2.50 francs per ton for private mines 

 and 2.15 francs per ton for Government mines, in 

 spite of the fact that the private operators sold their 

 coal cheaper than the Government. . . . Further 

 evidence of the better practice in the private mines 

 is afforded by the annual coal recovery per miner, 

 which in 19 13 was 261 tons for private mines and 

 229 tons for Government mines." 



Perthshire has been fortunate In that on two occa- 

 sions when there was a fall of meteorites specimens 

 and data of a trustworthy nature have been obtained. 



