276 



NA TURE 



[July 23, 1896 



the capital ic) of the column,- turning upwards and being 

 ■carved to represent the rattles on a rattlesnake's tail, 

 with the addition, in some instances, of a plume of 

 feathers. 



It is this peculiar form of capital which has done so 

 much to ensure the ruin of the fa9ades of the Chichen 

 Itzd temples : for the weight of the projecting tail tilted 

 the capital outwards as the wooden beam above it 

 ■decayed. 



Some of these queer-shaped capitals (c) can be found 

 lying on the slopes or at the bottom of the pyramidal 



foundations of the temples ;iand it is only m the case of 

 the Castillo, where the projecting tail has been broken 

 off, as shown in Fig. «, that the fagade of the temple 

 has escaped destruction. 



On page 132 it is stated that "the lintel beams of the 

 ■doorway (temple of the Tigres), three in number, and set 

 as indicated in the section, are covered with well-executed 

 glyphs." For "glyphs" must be here read "ornaments," 

 as there is no trace of any hieroglyphic inscription. 



I notice that in describing the painted mural decoration 

 of the interior of this temple no notice is taken of the 

 picture above the doorway of a human sacrifice, and I 

 greatly fear it must have disappeared since I traced it 

 in its already mutilated condition in 1889. 



Mr. Holmes was not able to attempt any detailed 

 examination of the great group of colonnades and temples 

 which lie to the east and south-east of the Castillo. These 

 I surveyed in 1889, but had no time to make satisfactory 

 •excavations, and I greatly envy Mr. E. Thompson the 

 ■opportunity he has of making a thorough exploration of 

 these most interesting remains. 



There is one point on which I hope Mr. Holmes will 

 give us some further enlightenment. On page 102 he 

 states, without quoting his authorities, that Chichen Itza 

 was occupied by its builders for nearly 200 years after 

 its discovery by the .Spaniards. 



I have endeavoured to show in my own account of the 

 ruins {Biol. Centr. Am., vol. iii. pp. 5-9), that the 

 statement that the Spaniards encamped at Chichen in 

 1528 must be received with caution, and neither Bishop 

 Landa, nor the report drawn up at Yalladolid in 1579, 

 appear to me to indicate any occupation of Chichen by 

 the Mayas at the time of the conquest, although it may 

 still have been held in reverence as a place of pilgrimage. 



Part i. of Mr. Holmes's report ends with the descrip- 

 tion of Chichen Itzd. The descriptions throughout are 

 lucid, and the illustrations numerous and excellent. All 

 students of American archaeology will eagerly look 

 forward to the succeeding issues, and will, I feel sure, 

 join me in hearty congratulations to Mr. Holmes on the 

 excellence of his work, and to the Field Columbian 

 Museum on having thus been able to utilise his services ; 

 and all of us, who have expensive scientific hobbies, must 

 wish that there were more Alison Armours in the world 

 to give such splendid and timely help to scientific 

 research. Alfred P. M.-^udsl.'^y. 



NO. 1395, VOL. 54] 



MEA.SUREMENT OF CLOUD HEIGHTS AND 

 VELOCITIES.^ 



'"PHE study of the form and motion of the clouds has 

 -'■ been a favourite subject with meteorologists and 

 physicists from the earliest times. Among the first 

 works, since the invention of printing, may be mentioned 

 one by J. .•\lkindus (Venice, 1507), dealing with clouds 

 in general, and one on the height of clouds, by J. Ber- 

 noulli, "Nova ratio metiendi altitudines nubium " 

 (Lipsiae, 1688). But it is only during the last quarter 

 of a century, since it has been recognised that cyclones 

 and anticyclones form part of the general circulation of 

 the atmosphere, that the importance of a systematic study 

 of the upper air-currents by means of clouds has been 

 fully ap])reciated. For this purpose various methods, 

 both with and without instniments, have been employed. 

 In 1878 the Meteorological Council decided upon under- 

 taking a series of experiments at the Kew Observatory, 

 with a view of obtaining records of the height and 

 velocity of clouds, by means of photography, for which 

 purpose cameras fitted with theodolite mountings, and 

 provided with altitude and azimuth circles, were used. 

 The results of subsequent investigations, in which the 

 exposure of the plates was effected by electrical means, 

 were published in the Procccdini^s of the Royal Society, 

 vol. xlix. p. 467. In vol. viii. p. loS, of the American 

 Metcorologicol Journal, Mr. Rotch gixes an account of 

 the measurements of cloud velocities at Blue Hill 

 Observatory, Massachusetts, by timing the move- 

 ment of shadows cast by the clouds at points whose 

 distance apart was known. During the present year, 

 owing to the action taken by the International 

 Meteorological Committee, cloud observations are 

 being made in all parts of the globe, and instructions 

 for the use of special instruments have been 

 drawn up, at the request of the Committee, by Dr. 

 Hildebrandsson, of Upsala. The majority of stations, 

 if they use instruments at all, restrict themselves to the 

 use of simple nephoscopes, which give the direction and 

 apparent velocity of the clouds, by means of a mirror 

 and graduated circles ; in these instruments the observ- 

 ations are not influenced by the effects of perspective, 

 which are the same in the skv and in the mirror. At 





some of the principal observatories theodolites and 

 photogrammeters are being used. Each of the last two 

 methods has its advantages and disadvantages ; theo- 

 dolites are simpler and cheaper, while photogrammeters 

 require a certain amount of skill in photography. The 



1 *' Wo]kenh<iheiimessungen," von E. Kayser {Schfiftcncier Naturforsch- 

 emUn CcscUscJtaft in Danzig, 1895) ; " Des principales m^thodes em- 

 ployees pour observer et mesurer les nuages," par H. H. Hildebrandsson et 

 K ' L. Hagstrom (Ups.-ila, 1893). 



