OcTOBEE 1, 1898.] 



KNOWLEDGE. 



235 



an affirmative reply has been given recently by the 

 eminent French astronomer, M. Camille Flammarion.* 



Some time ago he commenced observing the chestnuts at 

 Juvisy Observatory, near Paris, recording the days on which 

 leaves ami flowers were first seen. He has now a uniform 

 series of thirteen years of such records (188(5 — 18il8). He 

 draws a curve to represent (say) the date of first flowermg 

 of the chestnut, in this way : The dates, ranging from 

 4th April to 9th May, are first changed into numbers, 

 caUing the latest No. 1, the second latest No. 2, etc. Then 

 the thirteen years series of these numbers is smoothed 

 with averages of four (averaging the first four, then the 



■9 'li '!r '» 



issc '3 ■& '9 "62 'i- 's 'Yi 'V y '»o '3 '<• '9 V^ '-T 's 



A. — Sunspot Curve. B. — Smoothed Curve of first flowermg of 

 chestnuts, near Paris. c. — Smoothed Curve of return of Swallow to 

 Central France. D. — Smoothed Curve of average firet flowering of 

 five plauts in Hants. E. — Smoothed Curve of first flowering of Sibes 

 Sanguineum, Edinburgh. F. — Smoothed Curve of death-rate of male 

 persons, eighty-five and upwards, in England, (d, b, and F are 

 inverted curves.) 



second to the fifth, and so on). These smoothed values 

 yield the curve B in our diagram.! The thing to be noted 

 is, that high points in it represent early dates, and low 

 points late ones ; and there is good agreement with the 



* See Bulletin de la SociJU Astro nomique, for June, 1898. 



t I should perhaps state that these two curves, B and C, are not 

 an exact copy of M. Flammarion's diagrams, but are drawn from his 

 figures. The four year average is in each case put down to the third 

 year of the group (with sUght want of symmetry). These two 

 curves should be considered independently ; they are da-awn with the 

 same vertical scale for convenience. 



last sunspot wave (carve A), the earliest dates being near 

 sunspot maxima and the latest near minima. 



These data are obviously too meagre, however, to base 

 much upon, and M. Flammarion has recourse to several 

 longer records, showing the dates of return of some 

 migratory birds (the swallow, the cuckoo, the nightingale) 

 tt a place near Moulins, in the centre of France (the Pare 

 de Baleine). The longest record is that of the swallow, and 

 the smoothed curve for it (drawn on the same principle) is 

 that marked C. A correspondence of the same kind, not, 

 indeed, absolutely perfect, is here apparent. The swallow 

 returns later, on the whole, near minimum suuspots than 

 near maximum. The dates here range from 19th March 

 to 11th April. Curves of the two other birds are given 

 by the author as pointing to the same influence. 



With regard to temperature, M. Flammarion finds that 

 a smoothed curve of the mean temperature of March and 

 April (months of great importance to vegetation) corre- 

 sponds with the sunspot curve, and also fairly represents 

 the temperature variation of the whole year. 



Coming to our own country, we may, if I mistake 

 not, find the same influence at work ; and I may be per- 

 mitted to recall, in this connection, some curves which 

 have appeared elsewhere. 



D is a curve drawn from data in the Annual Keports 

 on phenological phenomena presented to the Royal 

 Meteorological Society. It represents the flowering of 

 plants in a district of Hants. The five annual dates of 

 first flowering of five plants (viz., coltsfoot, wood-anemone, 

 blackthorn, white oxeye, and dogrose) from 1878 to 1895, 

 translated each into the number of the day in the year, 

 are added together and an average taken. Then the series 

 is smoothed with averages of five (to get rid of minor 

 waves of variation). Here a high number represents the 

 opposite of what it does in M. Flammarion's curves, viz., 

 a late date, while a low number represents an earlier date. 

 The curve is an inverted one, the numbers increasing 

 downwards. E is a curve got similarly from a record of 

 the first flowering of Ribes Sanijuineum (or flowering 

 currant), at Edinburgh, 18-50-75. 



Both of these curves appear to indicate late flowering 

 about the time of sunspot minima, and early about the 

 time of maxima. 



Cold retards the beginnings, the first signs of life ; it 

 often accelerates the end of life. We know that a sharp 

 snap is fatal to many of the aged and the weak. The 

 Registrar-General's reports give us an opportunity of seeing 

 how the death rate of old psople varies from year to year. 

 If we take the series for males eighty-five and upwards, 

 and make a smooth (inverted) curve of it (F), we find it 

 has considerable suggestions of a relation to that variation 

 in winter cold whose effects we have been tracing, and the 

 origin of which, as of much else, may probably be found 

 where — 



" The very source and fount of day 

 Is dashed with wandering isles of night." 



ECONOMIC BOTANY. 



By John R. -Jackson, a.l.s., etc.. Keeper of the Museums, 

 Royal Gardens, Kew. 



ZYGOPHYLLE-E. — A family usually known as the 

 Guaiacum order, consisting of trees, shrubs, and 

 herbs, found abundantly and widely dispersed in 

 the tropical and warmer parts of the globe, the 

 spiny species being characteristic of the desert 

 vegetation of Egypt and Western Asia. Many of the 



* 6ee Lancet, January Ist, 1898. 



