July 23, 1908] 



NA TURE 



285 



at 58!. 13s. 4d. per mile per watering season, a figure wIucIt 

 contrasts favourably with the cost of tar painting and 

 approximates very 'closely to tliat of watering. In some 

 instances the material is applied hot, but Mr. Brown has 

 used it upon all the streets of the Southall-Norwood Urban 

 District in the cold state by means of an ordinary water- 

 ing cart, with excellent results. The appearance of the 

 road treated with oil-tar is that of a newly-laid wood paye- 

 ment, and the odour given off is similar. It is his opinion 

 that the use of both coal-lar and oil-tar will become pretty 

 general, the use of oil-tar being adopted where it can be 

 obtained, and coal-tar where oil-tar is not manufactured. 

 The employment of " akonia," calcium chloride, " hal- 

 mite," and' " pulvicide " is also considered in the paper. 

 But oil-tar is shown to possess certain advantages, more 

 especially of economy, oyer other methods. 



Mr. W. D. Scott'-Moncricff contributed a paper upon 

 " Some Recent Experiments on the Biolysis of Sewage." 

 The immediate objects of his investigation were to dis- 

 cover what periods of hydrolysis gave a sufficient standard 

 of purification with measured conditions of flow, and the 

 experiments are claimed to have shown, for the first time, 

 not only the behaviour of the sewage in varying cir- 

 cumstances of sojourn, &c., in the septic lank, but also 

 to what extent a well-matured filter working under proper 

 conditions is capable of dealing with the polluting organic 

 matters under widely varying conditions, as regards dif- 

 ferent periods of hydrolysis. It should be noted, how- 

 ever, that the author points out that the results he has 

 obtained are strictly confined to the special conditions ihnt 

 produced them, and that they do not justify any generalisa- 

 tions. 



A noteworthy paper upon " The Limit of School 

 Cliildren's Capacity for Attention " was read by Prof. W. 

 Phillips. After referring to the various experimental in- 

 quiries into this question, which have involved the use 

 of various forms of Mosso's ergograph, or fatigue recorder, 

 and Griesbach's iEsthesiometer, and many experiments de- 

 signed to test the rate of deterioration in mental work 

 done at different times of the day and on different days 

 of the week. Prof. Phillips discussed the useful results 

 which all this work has led to. His conclusions are as 

 follows : — 



(i) The various tests seem to agree on one point, viz., 

 that during an ordinary school session children can main- 

 tain a more even degree of attention, if one or two 

 intervals of rest are included. Where two of ten minutes 

 each can be arranged, more advantage is gained than from 

 one of twenty minutes. (2) The tests seem to agree, too, 

 in showing that a child's attention wanes more rapidly 

 in the afternoon than in the morning. Therefore those 

 teachers who have been accustomed to place the less 

 taxing subjects of instruction in the afternoon seem justi- 

 fied. (3) The various branches of mathematics seem, 

 ceteri paribus, to make a greater demand on the atten- 

 tion than most other subjects. This result has long ago 

 been anticipated by those teachers who place mathematics 

 early in the morning session. (4) Gymnastics is not of 

 necessity a mentally recuperative subject, some of the 

 tests proving that children were often tired afler a lesson 

 in it. {5) In connection with the discussion of the extent 

 of the fatigue caused by gymnastics, it soon becomes 

 obvious that the results do not depend on the nature 

 of the exercise alone, but also on the teacher. If the 

 latter is a strict disciplinarian, the fatigue may be of 

 a pronounced character. (6) It is clear that attention 

 depends on numerous factors, such as the age, health, 

 and nutrition of the child, the temperature and ventilation 

 of the class-room, &c. But above all it depends on the 

 child's training and education. 



RECENT METEOROLOGICAL PUBLICATIONS. 

 'T'HE report of the second Norwegian Arctic Expedition 

 -'- of 1898-1902,' edited by Dr. H. Mohn and published 

 at the expense of the Fridtjof Nansen fund for the 

 advancement of science, forms a valuable addition to the 

 meteorology of a liltle-known region of the earth's surface. 



1 Report of the Second Norwegian Arctic Exp^diiion in the Fratii. 1898- 

 IQ02. No. 4, Meteorology. Ry H. Mohn. (Kii...tiania: Pubhshed by 

 V'idenskabs-Selskabet i Kristiania, i;o7.) 



NO. 2021, VOL. j81 



The Vram left Christiania on June 24, 1898, and sailed, 

 via Godhavn, Upernivik, Foulkefjord, and Cocked Hat, to 

 the first winter quarters, which were reached in September. 

 As the methods of observation were different when the 

 ship was anchored from when she was under way, the 

 results are given separately, and as those obtained at the 

 winter quarters are most complete they are given in part i. 



The positions of these winter quarters and the length 

 of slay at each are shown in the following table : — 



Place I.at. N. Long. \V. Duration of stay. 



Rice Strait ... 7845-7 ... 74 S^'s ■■■ 1898, Sept. 19 to iSgg, . Inly a^ 

 Havnefj,,rd ... 76 29-4 ... 84 3-7 ... 1899, Oct. 2^ 10 190 ■, Au|;. 9 

 GaasefjoiJ I. ... 76489 ... 8839-5 ... 1900, Srpt. 18 10 1901, Aug. 12 

 II.... 76 39-S ... 8838-3 ... 1901, .Sect. 6 to 1902. July n 

 The interval August 12 to September 6, 1901, was spent 

 sailing about in the Gaasefjord. 



Up to June, 1899, Dr. Johan Svendscn— the physician 

 of the expedition— who had taken part in the examining 

 and comparing of the instruments before they left Norway, 

 was the meteorologist-in-chief, but his lamented death in 

 that month robbed the expedition of his further invaluable 

 services. 



The pressure observations were made with the same 

 barometer— a Kew standard Adie 850— throughout, and 

 readings were talcen every two hours from midnight to 

 midnight, k small number of records were, from one 

 cause and another, omitted, but the gaps have been filled 

 in by the interpolation of readings from a Richard baro- 

 graph. In the tables the values, reduced to standard 

 temperature, barometer, gravity, and sea-level, are given 

 for the bi-hourly readings eac'h d,ay ; daily and monthly 

 means, and the' monthly means for each even hour, are 

 also shown. The mean pressures for the months exhibit 

 a regular annual period, with a chief maximum in March, 

 a secondary maximum in November, a principal minimum 

 in .August, and a secondary minimum in January. The 

 range of pressure is ii-S'mm., and the yearly mean 

 pres^sure for the whole region is 761-40 mm. Other tables 

 summarise the lowest and highest pressures recorded, and 

 the differences between the mean highest and mean lowest 

 pressures in each month are given. The oscillation of 

 pressure is shown to be greatest in February and least in 

 .Xugust, greatest in winter, least in summer. 



Owing to the rolling of the From only a few of the 

 thermometers came back safely to Norway, but there is 

 sufficient evidence on which to base the discussion of 

 errors The reduced values for temperature are tabulated 

 in much the same form as those for pressure, and the 

 summaries show that during the "dark season 

 (November December, January), when the sun reniams 

 below the horizon, the diurnal variation vanishes entirely. 

 The daily range of temperature shows an annual period 

 with a maximum (3°-47 C.) in April ; during the three 

 summer months it is practically stationary at i 7 C. to 

 8 C The respective effects of clear and overcast skies 

 temperatures recorded are shown very clearly 

 With a " clear skv " in the months October to 

 j.u.^.., . the daily minimum' occurs in the day hours^and 

 the maximum atnight. but with an " overcast sky the 

 ordinary daily period obtains in every month. Dr. Mohn 

 suggests that the investigation of air temperatures in the 

 Arctic and Antarctic regions deserves greater attention, 

 the final results of which would probably throw consider- 

 able light on the question of radiation from and to the 

 earth in the lower atmosphere. 



The lowest temperature recorded by the expedition 

 {.-<^\°-\ C.) was obtained on January 20, 1901, a year that 

 was marked by unusually low temperatures, and the 

 hidiest (n°-3 C.) was recorded on July 9. 1902; thus the 

 absolute range becomes 64°-6. In the mean there are 

 about thirtv-four days per annum when the temperature 

 falls below' -40°; February is m.arked by exceptionally 

 birth maximum temperatures, especially in 1900. 



The other meteorological factors, wind, storms clouds, 

 precipitation, S:c., are dealt with by Dr. Mohn in a 

 simil.arlv comprehensive fashion, but enough has been said 

 to show that in this volume we have data of unique value 

 which should prove of great service in current meteorology. 

 The work h.as obviously been done with conscien lous 

 care and thoroughness ; the only pity is that the period for 

 which observations are available is so brief. 



on the 



(p. i'3)- 

 Januar}', 



