July 27, 1876] 



NATURE 



267 



chief features of this system of warnings are briefly 

 sketched in a recent number of the Bulletin Hebdoma- 

 daire of the Scientific Association of France. 



Weather-warnings intended to be useful to the agri- 

 cultural interest are essentially different from those issued 

 for the benefit of navigation. What sailors require 

 almost exclusively to know is, the force and direction of 

 the wind in approaching storms. On the other hand, 

 what agriculturists require to know is a knowledge of 

 coming rains and of thunderstorms, especially the de- 

 structive hail which often accompanies them ; whilst the 

 wind, save in rare exceptional cases, little affects them. 

 The ability to foretell rain, the causes of which depend 

 on conditions absolutely different in different parts of 

 France, is unquestionably one of the most intricate 

 problems of science, and therefore demands the closest 

 study, wide knowledge, and sound judgment in working 

 out its successful solution. 



When, eighteen years ago, the Paris Observatory, esta- 

 blished a system of warnings for the French Marine, the 

 conditions for carrying them out successfully were not 

 known. Now, however, owing to the experience ac- 

 quired, the observatory is able to issue warnings of so 

 useful a nature, that no serious storm makes its appear- 

 ance in the Channel, or on the shores of the Bay of 

 Biscay, or of the Mediterranean, which has not previously 

 been announced to the seaports menaced by it. To-day 

 the difficult question of agricultural warnings presents 

 conditions of uncertainty similar to those which warnings 

 for navigation presented in 1858. The present difficulty, 

 therefore, is no reason for doing nothing, but only a 

 reason for greater care and more strenuous exertion. 

 Mistakes will necessarily be made at the first, probably 

 numerous during the first year, seeing that there is still 

 no precise basis on which to rest ; they will, however, 

 diminish as experience is acquired, and doubtless the time 

 will by and by come when warnings for agriculture will 

 be attended with a like success as now characterises 

 warnings for navigation. 

 §P Agricultural warnings cannot, then, as in the case of 

 warnings for navigation, be issued to the provinces by the 

 Paris Observatory in an absolute form. It is, at this 

 early stage, indispensable that the warnings sent to the 

 chief places of the departments be of a general character 

 to be supplemented and modified by local meteorological 

 experts, who, in doing so, must be guided by their know- 

 ledge of the local peculiarities of their particular districts. 

 I This mode of procedure will furthermore lead to a 

 I thorough examination and a more exact knowledge of the 

 meteorology of France. 



The points to be more specially investigated by the 

 departmental Meteorological Commissions at the outset, 

 are these : — i. To follow and investigate the march of the 

 rainfall, not only as regards quantity, but as regards the 

 mode in which it is successively propagated from canton 

 to canton, and from department to department, particu- 

 larly when, after a season of drought, rainy weather 

 begins to set in. 2. As regards thunderstorms {orages), 

 the chief point to be attended to is that information of 

 their first appearance be sent to the chief place of the 

 department in which they occur, which, in its turn, will tele- 

 graph the fact to the Paris Observatory, so that the officials 

 there may, in view of the whole circumstances, send 



timely warnings to those departments which appear to 

 be threatened by the storm. 3. Since little is yet really 

 known of hailstorms, which are often so disastrous to 

 agriculture, it will be necessary to give instant attention 

 to collect such data as may likely lead to some knowledge 

 of the influence of woods, hills, and river-courses on the 

 origin and progress of the hailstorm. 4. In connection 

 with the late frosts of spring, which are productive of 

 such enormous loss to agriculture, the often-alleged effect 

 of smoke in counteracting* their blighting influence will 

 be brought to the test of experiment on a large scale, 

 say over the whole extent of a valley. 5. Lastly, warn- 

 ingsrelative to inundations cannot but excite the liveliest 

 interest, in consideration of the national disasters of 

 recent years, which might have been to a large extent 

 lessened, if not in many cases averted altogether, if a 

 proper system of such warnings had been in operation. 

 To the civil and mining engineers to whom these warn- 

 ings have been entrusted, the service of the agricultural 

 warnings will necessarily lend much valuable assistance. 



Agricultural weather-warnings began to be issued by 

 the Paris Observatory, on May i, to the three depart- 

 ments of Vienne, Haute- Vienne, and Puy-de-D6me, the 

 telegraphic authorities giving the free use of the wires 

 in the transmission of the messages. In order to give 

 a fair trial to this initial experiment the system will be 

 continued daily till October i, 1876, after which the whole 

 matter will be submitted to a careful reconsideration. 



The following example will show the method employed 

 in carrying out the system : — On May 7 the Observatory, 

 to show the general course of the isobarics over Europe, 

 telegraphed that the barometer at 32° and sea-level was 

 29"6o7 inches at Palermo, 29725 at Naples, Florence, 

 Perpignan, and Madrid, 29*922 at Moscow, Berne, Li- 

 moges, and Bordeaux, 30'i 19 at Petersburg, Paris, and 

 Lorient, 30*316 at Helsingfors, Helder, and Greencastle, 

 and 30*5 12 at Hernosand, and Skudesnes. Attention was 

 further drawn to the fact that pressure was not only high 

 in Sweden, but that it had risen 0*393 inch, and not 

 only low in Sicily, but had fallen 0*196 inch ; and that 

 since under this two-fold influence a polar current was 

 flowing over Europe towards the Mediterranean, northern 

 and easterly winds would continue to prevail, bringing with 

 them generally clear skies and, owing to the strong sun- 

 heat, an increase of temperature during the day. This pre- 

 diction, it is needless to add, was verified by the event. 



We most heartily wish every success to this bold and 

 novel system of weather-warnings, designed for the 

 benefit of great national interests. It may be added that 

 it is on a sound practical knowledge of the thunderstorm, 

 considering the term in its widest significance, that the 

 success of these warnings will depend ; and it is, there- 

 fore, singularly fortunate that in no country hsa so much 

 well-directed labour and expense been bestowed on the 

 investigation of thunderstorms as in France. 



RADCLIFFE'S " VITAL MOTION" 



Vital Motion as a Mode of Physical Motion. By Charles 

 Bland Radcliffe, Doctor ot Medicine, &c. (London : 

 Macmillan and Co., 1876.) 



AS there is a growing conviction of the importance of 

 studying physiology from the side of physics, so 

 we may be led to value more the efforts made in this line 



