February 12, 1920] 



NATURE 



641 



Both botanists and geologists will welcome the 

 second part of the memoir on the remarkable petrified 

 plants from the silicified peat-bed in the Old Red 

 Sandstone of Rhynie, Aberdeenshire, by Dr. R. Kid- 

 ston and Prof. W. H. Lang, just published in the 

 Transactions of the Royal Society of Edinburgh 

 (vol. Hi., No. 24, with lo plates). The genus Rhynia 

 and a new allied genus Hornea are described in 

 •detail and referred to a new family, Rhyniaceae, of 

 the class Psilophytales. These, and the other vascular 

 Cryptogams preserved with them, are the most ancient 

 plants of which the internal structure and external 

 appearance are adequately known. Rhynia and 

 Hornea have neither leaves nor roots, each consisting 

 merely of an underground rhizome, with long, uni- 

 cellular rhizoids, and a round aerial stem, dicho- 

 tomously branched, with sporangia at the ends. They 

 are the simplest known undoubted Pteridophyta, and 

 fundamentally more primitive, not only than all exist- 

 ing land-plants, but also than most of the plants of 

 the Upper Devonian and Carboniferous floras. Their 

 geological age is not later than that of the Middle 

 Old Red Sandstone of Scotland, and an apparentlv 

 related genus, Sporogonites, occurs in the Lower 

 Devonian of Norway. Several interesting comparisons 

 are made with existing Cryptogams, but the authors 

 wisely defer general conclusions until thev have 

 studied more of the associated plants. 



The Report of the Department of Mines of the 

 State of Mysore for the year 1917-18 gives a detailed 

 account of the results of the year's mining operations. 

 Naturally, gold-mining in the Kolar goldfield still 

 forms the preponderating part of the industry; it is 

 satisfactory to find that, in spite of the shortage of 

 skilled labour and the difficulty of obtaining supplies 

 owing to war conditions, there was but little falling-off 

 in the output, the production, amounting to 

 5.36.558-72 oz. of fine gold, being only 17,689-71 oz. 

 below that of the previous year. The number of acci- 

 dents shows an appreciable diminution, and it is 

 interesting to note that the dangerous effects of the 

 rock-bursts, to which this field is liable, have been 

 somewhat prevented by the new methods of supporting 

 the hanging wall by means of packs of waste rock. 

 Of the other minerals produced manganese-ore is the 

 most important; the output of this was 31,331 tons 

 as against 20,674 tons in the previous year. Chrome- 

 ore, magnesite, and asbestos are also produced in small 

 <juantities, whilst workings for mica, antimony-ore, 

 corundum, galena, and kaolin are proceeding on what 

 can, for the present, be described as a purely experi- 

 mental scale. 



Amongst the reports on the mineral resources of the 

 United States recently issued by the Geological Survey 

 of that country one of the most interesting deals 

 with the cement production in 1917. It is there 

 pointed out that the United States produced 93,000,000 

 barrels in that year, as against a production in Europe 

 of 72,000, cxK) barrels. An interesting account is also 

 given of the development of concrete shipbuilding. 

 The pioneer concrete ship was a small boat built in 

 France in 1849, followed in 1887 by a small vessel built 

 NO. 2624, VOL. 104] 



in Holland. In .\merica the first serious attempt was 

 commenced about 1912, when a number of concrete 

 barges were constructed, until in 1918 the Faith, a 

 sea-going vessel of 5000 tons, was launched at San 

 Francisco. It is stated that the percentage of dead- 

 weight to full-load displacement for vessels of 3500- 

 tons dead-weight capacity works out at 52 for con- 

 crete, 53 for wood, and 68-6 for steel, so that the 

 capacity of the concrete ship is considerably less than 

 that of the steel ship, although this drawback is to 

 some extent offset by the lower first cost of the con- 

 crete ship. Much attention is being paid to this 

 problem in the United States, the design of the steel 

 reinforcement and the production of cement of low- 

 specific gravity being in particular closely studied. 

 The report, though brief, contains much information 

 of value to those interested in this modern applica- 

 tion of reinforced concrete. 



The annual volume of the Journal of the Scottish 

 Meteorological Society recently published contains 

 papers of considerable interest which should be read 

 by meteorologists on both sides of the Tweed. In the 

 first article Lt.-Col. Gold discusses the relation of 

 meteorology to aviation, and directs attention to the 

 new calls which flying has made on the meteorologist. 

 Thus, for example, visibility and cloud-height, to 

 which little attention was directed in the dailv 

 weather service a few years ago, are now of great 

 importance, and provision must be made for such 

 observations in any modern system of reporting to a 

 central office. In another paper Dr. E. M. Wedder- 

 burn, who did much to advance the usefulness of 

 meteorology to gunners during the war, states the 

 nature of some of the problems met with in this 

 branch of the subject and of the solutions adopted. 

 In the old days gunners were content to use surface 

 meteorological conditions only in working out their 

 corrections. The introduction of the "ballistic wind" 

 and "ballistic temperature," which take account of 

 the changes of the meteorological elements at all 

 heights traversed by the shell, marks a great step 

 forward. A note by Capt. C. K. M. Douglas shows 

 what valuable information concerning the formation 

 of haloes and similar manifestations may be obtained 

 by flying among the clouds which give rise to the 

 phenomena; while an article by Capt. T. B. Franklin 

 on meteorology and agriculture w-ill appeal to a 

 different class of reader. 



The February issue of Conquest, the new popular 

 science monthly, gives, amongst other articles of in- 

 terest, ar^sumd of the first two of Prof. W. H. Bragg's 

 Royal Institution lectures to children on sound and 

 an article by Dr. Rosenhain on glass. In the latter, 

 which is well illustrated, it is pointed out how serious 

 the consequences of our former neglect of the scientific 

 side of glass-making might have been if we had not set 

 about repairing this fault in the early years of the 

 war. The author describes some of the difficulties 

 which have to be overcome before glass suitable for 

 scientific instruments can be produced. Impurities 

 from the melting-pots and enclosed air-bubbles account 

 chiefly for the large percentage of rejected glass, 

 which may reach 80 per cent. Before the war glass 



