358 



NATURE 



\_August 30, 1877 



to be urged on behalf of so confusing a practice. When 

 a man has a new genus to describe it should be his first 

 duty to take care that he does not apply to it a name that 

 has been proposed before, and it is not generally difficult 

 to find this out. Of course the punishment ultimately 

 falls on the offender's own head, for in these days some- 

 body is sure to discover the blunder, and generally before 

 long, but meanwhile the inconvenience may be and often 

 is not inconsiderable. 



In conclusion, we have but to wish the Zoological 

 Record Association an increasing sale for their useful 

 annual, and to express our thanks to Mr. Rye and his 

 assistants. 



ARCTIC METEOROLOGY 



Scientific Results of the United States Arctic Expedition 

 Steamer ^'■Polaris" C. F. Hall commandino. Vol. I. 

 Physical Observations. By Emil Bessels, Chief of the 

 Scientific Department, U.S. Arctic Expedition. 



THE United States Government has, with its accus- 

 tomed liberality to science, published in a bulky volume 

 of about 1,000 pages, under the auspices of the National 

 Academy of Sciences, the results of the various observa- 

 tions of meteorology, astronomy, and magnetism, made 

 by th'e scientific staff of the Polaris during the expedition 

 to the Arctic regions in 1871-73. In the present notice 

 we shall refer only to the barometric observations, and 

 the discussion of them, which occupy altogether forty- 

 three pages of the volume before us. 



The barometric observations were made hourly at 

 Polaris Bay, 81° 36' lat. N., 62° 15' long. W., from 

 November, 1871, to August, 1872, and at Polaris House 

 from November, 1872, to May, 1873, and they are pub- 

 lished in extenso in this volume. These observations we 

 have examined, and it is evident that they have been 

 made with great care, and that, taken as a whole, they 

 form one of the most valuable repositories of facts which 

 we possess illustrative of the meteorology of the Arctic 

 regions. The errors which do occur are of that class 

 which may be regarded as " inevitable" in such a record of 

 observations, viz., typographical errors, transposed or 

 changed figures, and personal errors of observation which 

 are well known to meteorologists, and admit of easy 

 detection and correction. 



On turning to the table of the mean hourly values for 

 the different months (p. 18) calculated from the data just 

 mentioned, we are at once struck with the extraordinary 

 character of the hourly curves as disclosed by these 

 figures, inasmuch as they show a repeated abruptness of 

 change and a capriciousness of form which certainly 

 could not be accepted unless on the clearest proof that 

 they represent well-ascertained facts. 



In examining the mean hourly values for December, 

 187 1, the first month for which complete observations 

 were made, it is seen that the calculations made from the 

 individual observations are all correct. If we, however, 

 take the trouble to critically examine the observations 

 themselves from hour to hour, it is seen that there occur 

 two uncorrected readings of 29'37i and 29777 inches, 

 instead of 29-571 and 29-577 inches, and twelve uncor- 

 rected readings in which the observers, as occasionally 

 takes place with the best observers, have read the instru- 



ment 0-050, o-ioo, or 0-150 inch either too high or too low. 

 Correcting, then, these observations, and calculating 

 afresh the hourly values, we obtain the result given in the 

 following table (columns A.), to which are added the 

 hourly values as printed in the volume (columns B.) : — 



Thus, from not submitting the observations to a pre- 

 liminary critical examination before calculating the 

 averages, half of the resulting averages are faulty, and 

 a monthly curve is obtained which completely fails to 

 represent the physical datum for the ascertaining of 

 which this elaborate set of observations were carried on 

 in all the rigours of an arctic winter. 



We are the more desirous of urging this matter on the 

 attention of meteorologists, because the same method of 

 hasty and ill-advised discussion of barometrical ob-erva- 

 tions is widely practised ; and, it need scarcely be added, 

 results in the publication of generally accepted averages, 

 which more than anything else are seriously obstructive 

 to any real progress in this intricate but vitally important 

 branch of physical inquiry. 



The observations for June, 1872, are free from these 

 errors of observation, but notwithstanding this the hourly 

 monthly values which have been deduced from them do 

 not appear to be satisfactory. On calculating, then, the 

 monthly values from the observations of this month, it 

 turns out that only one of the twenty-four means is correct, 

 the other twenty-three being more or less seriously in 

 error. It is to be regretted that the hourly means for the 

 other months of the period also are so much and so 

 frequently in error, those for December, 1872, for instance, 

 giving a curve which in its essential points is the reverse 

 of the correct one, that the whole of the elaborate dis- 

 cussion of the barometric observations made by the 

 scientific staff of the Polaris Arctic Expedition must be 

 rejected. 



The averages for the different months have been deduced 

 in two ways, viz., from the twenty-four hourly means, and 

 from the thirty or thirty-one daily means of the month. 

 These two sets of averages would of course agree if the cal- 

 culations were correct. In the printed tables they are made 

 to agree even to the thousandth part of an inch, by simply 

 placing the calculated average of one column under both 

 columns. Thus the monthly average of June, 1872, is, as 

 deduced from the twenty-four printed hourly means 29-888 

 inches, and as deduced from the thirty printed daily 

 .means 29-860 inches, but in the tables 29-888 inches is 

 printed as the mean of both columns. It is thus evident 

 that the reduction of this very important series of baro- 

 metric observations requires yet to be made — a work 

 which we hope will be yet undertaken, particularly since 

 the summer and the winter means we have computed seem 

 to suggest important connections between these arctic 

 barometric curves and the curves of lower latitudes. 



