April 6, 1888.] 



SCIENCE 



165 



peculiarity which attracted my attention was apparently the two 

 circles of maximum intensity, — the mountain-line, and the one 

 indicated by the destroyed and injured towns. The solution is for 

 you. But the thought has obtruded itself in my mind, why cannot 

 there be areas of re-enforcement in earth as in water waves, where 

 a succession of small impulses are followed by an aggregated one? 

 This by reflection and accumulation of successive shocks from the 

 focus. Of course, the point could be placed on the isoseismal of 

 the towns, or considered as areas of characteristic epicentral dis- 

 turbance. 



Noteworthy is the immunity of Bacerac and San Miguel ; the 

 former nine miles south, the latter three and one-half miles to the 

 north, of Babispe. Though the energy of the shock was undoubt- 

 edly great, no serious damage was inflicted, save to the feelings of 

 the inhabitants ; and the degree of religious frenzy originated, more 

 than compensated for the lack of seismic perturbations. They can 

 be put on the isoseismal of Tombstone. 



" Of the effects of the temblor, none have been of greater inter- 

 est or more importance than the modification of the water-supply 

 of the shaken district. During the first shock, all over the area of 

 severe and even moderate vibration, the phenomena of water-cra- 

 ters were e.xhibited. This, however, was merely a temporary affair, 

 the flow ceasing as soon as the violent shaking was over. It is the 

 permanent re arrangement of the water-distribution which we have 

 to consider. Many apocryphal stories have been told of the won- 

 derful increase of water in the Yaqui and other streams immediate- 

 ly succeeding the earthquake. In addition to the outpouring of the 

 crater water, many springs were made. This latter effect was not, 

 however, an instantaneous one. In most of the rivers and springs 

 where there has been increase, at first they went almost dry ; then 

 in a few days or weeks was a gradual augmentation of water, this 

 antedating the rainy season. At the present time there is an alter- 

 ation in the water-supply, with others, of the following streams and 

 springs : the rivers of Fronteras, Yaqui, and San Bernardino ; the 

 springs of Penuelas and several others with uncertain names ; the 

 arroyos of the passes, Elias, Elisu, and Cabellera. Most important is 

 the Yaqui River. This gradually gained in volume after the first 

 diminution, until the flow equalled its midwinter amount. The San 

 Bernardino is now flowing from head to mouth, a thing never before 

 known at this season of the year, and is said to be gaining. Several 

 important springs on the eastern side of the mountains, opposite 

 Babispe in Chihuahua, were increased in size, notably Penuelas on 

 the Carretas Ranch. A number of entirely new springs were 

 started. In fact, over the entire central seismic region, the water- 

 supply has visibly augmented. In considering this, the effect of an 

 unusually severe rainy season must be estimated. 



"The rainy season of 1887 has been unequalled since 1881. 

 There was, however, an unquestioned gain of water before this set 

 in. But when it did come, there was nothing by which one could 

 judge whether a specified enlarged flow was due to rain or tem- 

 blor. The summer rainfall has been added to greatly by an ex- 

 traordinary winter downpour. Altogether, there has been sufficient 

 celestial increment to throw considerable doubt on the proximate 

 origin of the terranean and subterranean surplus. Unlike the 

 treasury surplus, there is no need of reduction. It is required. 

 By reason of this extraordinary quantity of aerial moisture, the es- 

 timate of the value of the quake to the country must be held as 

 subject to modifications in the future, should a dry season super- 

 vene, and demonstrate that the abundance of water was due to the 

 heavens, not to the earth. One cannot contemplate the San Bernar- 

 dino valley without believing that such stupendous changes as are 

 there manifest must have caused some permanent alteration in the 

 subterranean reservoir, — either increment or decrement. And if, 

 at the lapse of a year, a decided increase is noted, as has been, the 

 former result must be concluded to have taken place. 



" It will be noted in all reports that the direction of the first 

 shock is given as from west to east. This, perforce, in most in- 

 stances can be nought but error, especially on the line of the rail- 

 roads from Guaymas north. But let us consider the case of the 

 Sulphur Spring valley. At the time of the primary quake a cattle 

 round-up was going on at the station called Abbott's Ranch. The 

 house is near the centre of the valley, which is here nearly thirty 

 miles wide, and thoroughly waterlogged. There is no running 



stream ; but over its entire area water exists, from a few feet in 

 depth on the margin, to but a few inches in the centre, which is full 

 of swampy holes. It is a mass of alluvium, neither the mesas nor 

 the bordering ranges on the west or east encroaching much on the 

 margins. All reports from this place (and I have interviewed at 

 least thirty of the one hundred or less men present when the first 

 shock occurred) say it came from the west. The explanation I 

 have to advance for this may or may not be a tenable one. It is 

 this : in all earthquakes, near the central region there is what may 

 be called a 'resonant area ' preceding the vibratory movements of 

 the earth. This, in the temblor of May 3, antedated the onset of 

 the tremors a sufficiently long time to have passed to the west and 

 north-west at the instant the shake began. Of course, the noise 

 being in the west, the origin of the simultaneous terranean move- 

 ments was of necessity located there. This, however, does not en- 

 tirely answer for the Sulphur Spring valley. There they claim to 

 have seen the rocks falling and the dust rising on the western side 

 of the valley first, and some seconds later the same phenomena on 

 the eastern. I am inclined to think that this is to a certain extent 

 true. My reasons are the character and continuity of the mountain- 

 ranges extending from the western side of the epicentral area to the 

 western portion of the valley, and the nature of the valley itself. 

 The rate of vibration and wave-propagation must have been modi- 

 fied by passing through so saturated and heterogeneous a mass as 

 the latter. The mountains are not actually continuous between the 

 points mentioned, but there is less breaking, therefore slighter ap- 

 parent chance of mterruption, on that line than any other; and it 

 seems not an iinprobable or impossible hypothesis to assume that 

 the waves, both 'of sound and of movement, were propagated along 

 that line most rapidly, and did reach the western side of the valley 

 anterior to the time they made their appearance in the east. If this 

 be not the solution of such united testimony, it must be solved in 

 some other way. I think the time-data indicate this view of it, 

 though in this you must be the judge. 



" Among other seqiiellce, the mountain-fires which the effects of 

 the earthquake were the sole factors in originating, were due to 

 two causes, — falling bowlders and the emission of ignited gases. 

 The Sierra Madre fires were, beyond question, synchronous, and 

 arose similarly. The evidences of gaseous irruption were few but 

 striking. Primarily were the statements of many who claim to 

 have seen streaks of flame at different points, in the course of the 

 first night in particular, and several times thereafter during suc- 

 ceeding days and nights while the heavy shocks continued. This 

 evidence might have been a subjective sensation purely, due to in- 

 herent mendacity, or phenomena of fright similar to the stellar 

 exhibition of syncope. The objective testimony cannot, I believe, 

 be gainsaid. The shifting of such a tremendous mass of earth 

 must have had some concomitant phenomena ; and, if water and 

 gas shot out to varying but moderate altitudes, why should not 

 ignited gas do the same ? It did ; and the evidence was found in 

 several places, both in the river-beds and in the hills along the line 

 of faulting. This consisted of cinders about the margins and on 

 the walls of the river-fissures, and the discovery of burnt branches 

 overhanging the edges of such places, as weU as the same testi- 

 mony on some of the hills and mountains near the main fault. 



" Anywhere near one hundred and fifty miles of the centre the 

 energy of the shocks was considerable. All along the Sonera 

 Railroad, from Guaymas to Nogales, and from the latter place to 

 Benson, Tucson, El Paso, and as far north as Albuquerque, gen- 

 eral alarm was excited. From Charleston to Benson, in the San 

 Pedro valley, was a section of quite violent and terrifying motion. 

 Water-tanks slopped over, cars were set in motion on the track, 

 chimneys thrown down, buildings cracked, and water spouted up 

 from the ground. The last-mentioned phenomenon was not ex- 

 hibited north of Fairbanks. The track sank and bent at a pomt 

 where it runs in an east-and-west course, about two miles west of 

 Fairbanks. The convexity of the bend was south. These villages 

 and stations are in the narrow, alluvial bottom of the river-course. 



"At Batepito are some old adobe houses. They were frail and 

 in ruins many years anterior to the earthquake, but it is remarkable 

 that the remaining walls were not prostrated by the shock. Of 

 course, some of the upper portion was broken off, and one or two 

 having roofs crumbled in. Such structures in Babispe, Opotu, 



