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NA TURE 



[December io, 1908 



No meteorological theory has yet been discovered in the 

 Babylonian tablets, of which, of course, only a small 

 number has been preserved, and even a smaller number 

 deciphered. But I was quite recently greatly surprised 

 to find that the Babylonians had the windrose of eight 

 rhumbs, and used already the names of the four cardinal 

 points to denominate the intermediate directions; whereas 

 it was until now generally supposed that we owe to Charles 

 the Great, or perhaps to his learned monk Alcuin, who 

 came from Yorkshire, this progress of the combination of 

 the four principal winds to denote all others. That was 

 indeed a great advance, for it is w-ell known that in the 

 Greek and Roman periods each wind had its peculiar name. 



-Fragment of Parapegn 



in the 



a practice still in use amongst the Italian mariner 

 Mediterranean. 



From the Babylonians to the Greeks is a far cry, but 

 there is also great progress from a meteorological point 

 of view. It seems that the Greeks were the first to make 

 regular meteorological observations, some results of which 

 are still preserved, and that their great capacity for pure 

 science induced them to establish meteorological theories. 



My first statement is not only proved by Theophraslus, 

 who quotes several nien in .Asia Minor and Greece making 

 meteorological observations, but also by the interesting 

 fact that since the time of Meton, namely, since the fifth 

 century B.C., in the so-called parapcgmata {napawfiyiiara), 

 a kind of peg almanac fixed on public columns, the 

 general data of the weather resulting from observa- 

 tions were exhibited. As these weather-almanacs 

 differed from town to town, it clearly follows that 

 they were based on individual observations made in 

 each district. 



Here is an example taken from the parapegina of 

 Geminos, whose book, entitled " Introduction to the 

 Phenomena," is of special value for this ques- 

 tion : — 



August 31. — The shoulders of Virgo are rising. 

 The winds called irriaiai cease to blow. 



September 5. — Rising of Arcturus. South wind, 

 rain, and thunder. 



September 12. — The weather will likely change. 



September 14. — .Mostly fine weather for seven 

 days, thereafter easterly winds. 



Fig. I shows a fragment of such a parapegina 

 found recently at Miletus, and now preserved i 

 museum at Berlin. 



In the holes which can be seen in the marble stone 

 little wooden pegs were put in order to fi.-c the beginning 

 of the year and the days, which gave rise to the name 

 parapegma, derived from the Greek verb ■!rapairriypii/ai = io 

 fix into. 



It is not surprising that in these parapegmata the 

 observations of the wind prevail over all others, for they 

 were of practical use to navigation and easily made. Also, 

 the origin of the winds has always been a favourite sub- 

 ject of speculation among the Greek philosophers. In 



NO. 2041, VOL. 79] 



the epoch of Homer winds were still conceived as absolute 

 beings like gods, whereas Anaximander of Ionia, who 

 lived in the fifth century B.C., is the first to give a scien- 

 tific definition of the wind, which is still valid. He says : 

 ivifioy f'lvat l>v<ni' aepos, the wind is a flowing of air. 



It is therefore quite natural that the Greeks, even at 

 this early period, used wind-vanes, which represent the 

 older meteorological instrument, and a most interesting 

 example of it is preserved in the " Tower of Winds " at 

 Athens. 



At the time of the construction of the tower, namely, 

 in the first century B.C., a great man}' wind-vanes were 

 already in use, for a contemporary Roman writer, 

 Terentius Varro, tells us that in Roman villas 

 they were constructed in such a manner as to 

 show the direction of the vane on a windrose 

 fixed to the ceiling of the room (" ut intus scire 

 possis "). 



Soon after these earliest qualitative observa- 

 tions of the weather and direction of the wind 

 we find the first quantitative ones, that is to 

 say, the measurement of rain, in the first cen- 

 tury .A.D. It was made in Palestine, where the 

 great influence of rainfall on the crops must 

 have been fully appreciated at an early date, and 

 the results of which observations arc preserved 

 in the Mishnah, a collection of Jewish religious 

 books apart from the Bible. It seems to me 

 most interesting to state that the amount of 

 rainfall then considered as normal for a good 

 crop corresponds pretty closely with that deduced 

 * from the modern observations made by Mr. 



Thomas Chaplin at Jerusalem, whence it can be 

 inferred that the climate of Palestine has not 

 changed. 



Many of my audience will perhaps be 

 astonished when I state that we are indebted 

 also to antiquity for the first idea of a 

 most important modern meteorological instrument. Most 

 men of science are still of the opinion that antiquity 

 achieved nothing concerning physical instruments and 

 experiments ; but the more we become acquainted with 

 the scientific and technical literature of the Greeks and 

 Romans, which at present is often the subject of study 

 of philologists in preference to the classical authors, the 

 more we learn their many positive results in this respect. 



There are two physicists of special interest to us in this 

 connection, namely, Philo of Byzantium, who lived in the 

 third century u.c, and Hero of Alexandria, whose century 

 is not yet settled, but who certainly lived after Philo and 

 the great mathematician .Archimedes, both being quoird 



the 



by him. In the writings of these two physicists we find 

 the description of an apparatus which represents the 

 primitive idea of the thermoscope. 



Philo's description in his work " De ingeniis spirituali- 

 bus " (on pressure engines), the Greek original of which 

 is lost, only an .Arabian and a Latin translation being 

 preserved, v.'ill be made intelligible by Fig. 2. He says : — 



" One takes a leaden globe of moderate size, the inside 

 of which is empty and roomy. It must neither be too thin 

 that it cannot easily burst, nor too heavy, but quite dry 

 so that the experiment may succeed. Through an aper- 

 ture in the top is passed a bent siphon reaching nearly 



