March 30, 1899] 



NA TURE 



523 



most prominent. Of the number represented, either by entire 

 specimens or by fragments, not only do the greater part exhibit 

 technical qualities identical with the pottery from Copan, but 

 especially in the conventional use of certain decorative motives, 

 and in the employment of a graphic system common to that of 

 the Codices and to the sculptured monuments of Maya, these 

 affinities are very manifest. The same relationship makes itself 

 felt, although in a less striking manner, in the other classes of 

 objects. It is not claimed that this relationship, however 

 intimate, covers the whole ground, or that there is any homo- 

 geneity throughout the whole body of ceramic products, as if it 

 were the work of a homogeneous people and represented a 

 culture developed from within. On the contrary, there is in 

 the tendency towards diversity of type strong evidence of an 

 admixture of races, or of extensive importations derived from a 

 variety of sources. " 



The relation which the art of the Uloa Valley and the other 

 confines of the Maya area bears to that of the great central 

 Maya ruins is a matter of the deepest interest to arch.'eologists. 

 Although it is much to be regretted that Mr. Gordon is 

 prevented from continuing his interesting researches amongst 

 the ruins of Copan, it is no small satisfaction to know that he 

 has found other work to do, in which his knowledge of Maya art 

 will be fully utilised. 



A most interesting series of photographic and other plates 

 accompanies the "Memoirs.'' 



A NEW VERTICAL COMPONENT MICRO- 

 SEISMOGRAPH. 

 'X'HE microseismograph, devised a few years ago by Frof. 

 Vicentini, of Padua, is now well known as one of the 

 most valuable of the vertical pendulums used in Italy for re- 

 cording earthquake movements. With the aid of Dr. G. Pacher, 

 several improvements have been made in it, the latest being 

 the construction of a microseismograph for recording the vertical 

 component of the motion (Atti del K. ht. Veneto i/i scieiize, 

 &c., vol. Ivii., 1S99, pp. 65-89). In many of the details, it 

 closely resembles the older instruments adapted for the hori- 

 zontal components only. The chief points in which it differs 

 from the latter are the following. The pendulum consists of 

 a bar of iron i'5o m. long, 75 mm. wide, and diminishing in 

 thickness from 10 mm. at one end to 7 mm. at the other. 

 Near the thin end the bar carries three discs of lead, weighing 

 altogether about 45 kg. The other end is fixed in a bracket 

 built into the wall, and so inclined that the bar, under the 

 action of the heavy mass, is horizontal at the free end. The 

 magnifying and recording apparatus consists of two levers made 

 of aluminium tube. One of these, bent at right angles (the 

 longer arm being vertical), is connected with the pendulum, and 

 transforms its vertical movements into horizontal ones. The 

 second lever is horizontal, and its longer arm ends in a fine 

 thread of glass, the point of which records the movements of the 

 pendulum, magnified about 130 times, on a strip of smoked 

 paper which passes below it at the rate of 24 mm. per minute. 

 The first experiments showed that for rapid vibrations the 

 heavy mass remained in a practically stationary condition. Every 

 passing carriage produced a group of rapid vibrations, with 

 periods varying from one to two-tenths of a second. During 

 the short time in which the instrument has been at work, several 

 earthquakes have been registered, and Drs. Vicentini and 

 Pacher have increased the interest of the vertical component 

 records by appending also those of two other microseismographs, 

 giving the horizontal components only. These show that the 

 vertical movement predominates during the whole of the time 

 when the ground vibrates rapidly in a horizontal direction ; and 

 that the same sudden changes of intensity characterise the seis- 

 mograrns of both apparatus. The new instrument also records 

 the slow pulsations which follow the rapid vibrations, but much 

 less distinctly than the vertical pendulums, and it con.sequently 

 sooner attains a state of rest. 



THE STUDY OF WAVES. 



A CLAIM for the recognition of the study of wave structures 



of the earth's surface as a distinct and not unimportant 



branch of geography was advanced by Mr. Vaughan Cornish at 



the Riiyal Geographical Society on Monday. For the study he 



NO. 1535, VOL. 59] 



proposed the name kumatology, from xO/ua, a wave. Mr, 

 Cornish illustrated numerous forms of waves by means of lantern 

 slides, and described in detail some curious waves, of which 

 photographs were shown, which travelled up-stream, not as a 

 " bore,'' but without ch.inge or form. These may be observed 

 in streams which plough their way through sandy beaches to the 

 sea. The water-wave was really controlled by a submerged 

 sand-wave, the up-stream flank of^ which was exposed toaheavy 

 shower of sand from the turbid water. The stream being shallow 

 and its surface in waves, the crest of the water-wave was pushed 

 up-stream as the up-stream flank of the sand-wave received ad- 

 ditions of material. The scour of the water was thereby de- 

 flected, and the lee slope of the sand-hill was scoured away just 

 as fast as the weather slope grew. Thus the sand-hill moved 

 up-stream, although every particle of sand and every particle of 

 water travelled down-stream. Mr. Cornish showed photographs 

 of ripple-marks mimicking organic forms, and of rippled clouds, 

 and the ripple-ridging of hill-sides, and went on to deal with the 

 rippling of sand by wind, of which he has made a special study. 

 Tables of measurements were exhibited which proved that the 

 shape of these ripples was approximately constant for wave- 

 lengths from I to 145 inches. The shape was the same in 

 desert sand as in the sand of the seashore, the mean ratio 



— - — being I7'6 for the blown-sand ripples of the shore, and 

 height 



i8'4 for those of the desert, difference 39 per cent. He had 

 succeeded in reproducing these ripples by the action of a steady 

 artificial blast upon ordinary heterogeneous sand, but artificially 

 assorted sand containing no fine particles was not thrown into 

 ripples. For this it was necessary that there should be particles 

 fine enough to be tossed away by the eddy which forms in the 

 lee of the larger grains. Similarly the formation of sand reefs 

 or waves had been observed in the Mississippi when the mixed 

 detritus begins to settle, the finer stuft being churned up from 

 the bottom, and swept away, leaving the coarser materials ar- 

 ranged in ridge and furrow. Sand-dunes were built up by the 

 wind on similar principles. Photographs of desert sand-dunes 

 were shown, one of which exhibited the recent encroachments 

 of sand which have buried the road between Karachi and Clifton. 

 The sand-dunes here are advancing as a train of waves before 

 the south-west monsoon. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



A GENTLE.MAN who desires to remain anonymous has offered 

 to give 25,000/. towards the proposed Birmingham University on 

 condition that a sum of 225,000/. is previously subscribed. The 

 amount already promised is 135,000/. Under the terms of the 

 gift the 225,000/. must be obtained within one year from now. 



The Paris correspondent of the Chemist and Druggist ?XsX&% 

 that M. Dabout, doyen of the Paris Faculty of Sciences, and 

 Prof. Lippmann are to represent the Paris University at the 

 jubilee celebrations of .Sir George Stokes at Cambridge next 

 June. The Faculty of Medicine and the School of Pharmacy 

 will send delegates to the Congress to be held at Berlin from 

 May 24 to 27, for the purpose of studying the means of combat- 

 ing tuberculosis, especially amongst the lower classes. 



On the recommendation of the Lord-Lieutenant the Queen 

 has approved of the appointment of Prof Alexander Anderson 

 as president of the Queen's College, Galway, in succession to 

 Mr. 'W. J. M. Starkie, who has become Commissioner of 

 National Education in Ireland. Prof Anderson was a student 

 of Galway, and has held for many years the chair of Natural 

 Philosophy in the College, which chair he will retain. He was 

 a high w-rangler at Cambridge, a Fellow of Sidney Sussex College, 

 and also a Fellow of the Royal University of Ireland. He is 

 well known for his many contributions to the literature of 

 physics, and for the manner in which he has developed the 

 science school in the Galway College. 



An interesting investigation has just been commenced in the 

 engineering department of the Massachusetts Institute of 

 Technology. "The object is to determine the modulus of 

 elasticity or the deflection due to a load applied for a long 

 interval (in this case, a year) in comparison with that due to a 

 suddenly applied load. It appeared from tests made many 



