― 374 ―

Number of Maxima in the Main Shock

In response to various circulars sent out by the Commission, and to direct inquiries by the members of the Commission or their aides in the field, 154 replies have been received, which constitute testimony as to whether the main shock comprized one or more maxima. Many of these replies are rather questionable scientific evidence, inasmuch as many of them were in response to a leading and suggestive question, and very few of them have been subjected to the clarifying process of cross-examination. So few people were awake at the time the shock began that but a small proportion of the replies come from people who were in full possession of their observational faculties at the beginning of the disturbance; and of those who were suddenly and rudely awakened, few were sufficiently alert for deliberate perception at the time and had to rely upon a somewhat confused memory for the character of the shock. Yet the testimony is of value, and indicates a very general consensus of the impression that there were 2 principal maxima in the shock; and the failure of many to recognize or remember 2 parts to the shock does not seriously invalidate the testimony of those who received that impression.

Of the 154 replies received, 98 testify to 2 maxima; 46 to but one maximum; 9 to 3 or more maxima; and 1 to more than one. Of the 98 who reported 2 maxima, 67 discriminated between the 2 parts of the shock, as to their relative intensity; and of these 67, there were 48 who had the impression that the second maximum was the more severe, and 19 who thought it the less severe. Of the 46 who recognized only one maximum, 32 were beyond the zone of destructive effects, where the intensity was VI or less (in a few cases VII); and of the remaining 14 cases within the zone of destructive effects, 11 were offset or contradicted by other reporters in the same general district as themselves, who record two maxima. It would thus appear that within the zone of destructive effects, say out to isoseismal VII, the evidence, such as it is, points unmistakably to the occurrence of 2 maxima; and the prevailing opinion is that the second was the stronger. The failure on the part of many reporters to discriminate 2 parts of the shock beyond the isoseismal VII is not surprising, and is offset by the considerable number of reports in which 2 maxima were noticed.

List of observations as to the number of maxima in the earthquake shock                                                                                                                                                                                                                                                                                                                              
Locality.  Reporter.  No. of Maxima.  Remarks. 
Nolton  Clara Ward  2  Second stronger. 
Crescent City  G. Sartwell  2  Interval about 2 seconds. 
Montague  C. H. Chambers  1  Duration 30 seconds. 
Upton  G. R. Dixon  1 
Big Bar  W. A. Pattison  2  A tremor which eased up, then another stronger. 
Papoose  C. B. Lakemore  1 
Eureka  A. H. Bell  1  Maximum intensity toward end; duration 47 s. 
Fortuna  D. L. Thornberry  2  One greater than the other. 
Pepperwood  J. F. Helms  2  Second stronger. 
Briceland  J. W. Bowden  2  Second stronger. 
Fort Bragg  E. Huggins  2  Continuous shock, 40s., ending with heavy one. 
Glen Blair  A. P. Scott  1 
Albion  J. Coyle  1 
Philo  J. L. Prather  2  About the same intensity. 
Fish Rock  J. F. McH  2  Second stronger. 
Annapolis  G. W. Fiscus  2  First in wave motion; second rotatory. 
Fort Ross  G. W. Call  Several  Increased in force up to third or fourth. 
Cazadero  E. H. L. Cowley  2  Second stronger. 
Hemlock  C. D. L. Bowen  2  Second stronger. 
Cloverdale  M. C. Bale  Several  Oscillatory, ending with series of shocks. 
Lakeport  J. Overholser  1 
Sanhedrin  V. L. Frasier  1 
Oathill  J. J. Hulter  2  Second stronger. 
St. Helena  F. Blachowski  2  Second stronger. 
Veteran's Home  A. Brown  1 
Wooden Valley  H. W. Chapman  2  First stronger. 
Cotati  C. L. Jeffrey  1 
― 375 ―
Vallejo  J. J. Lindunger  2  Increase in severity in latter half. 
Tamalpais  W. W. Thomas  2  If any difference, first stronger. 
San Rafael  L. Reubold  2  First light and long, second hard and short. 
San Rafael  E. Landon  1 
San Rafael  A. Scott  2  First light, second heavier. 
San Rafael  G. L. Richardson  2  First heavier. 
San Rafael  F. M. Watson  2  First lighter and longer than second. 
San Rafael  J. D. Bennett  2  First heavier. 
San Mateo  B. A. Peckham  3  First and second were heavy wavy motions; third was short rapid trembling. 
San Mateo  R. Anderson  2  Two main thrusts or sets of movements. 
Mountain View  A. M. Free  2  Second stronger. 
Woodside  H. O. Beaty  2  Personally observed but 1; others observed 2 or 3 and there is a general agreement that second was stronger. 
San Jose  J. C. Hartzell  2  Second more intense. 
San Jose  M. Connell  1  Came suddenly, explosion-like, then a violent swaying. 
Santa Clara  J. S. Ricard  2  Two shocks, then finally a twist and an uplift. 
Campbell  F. M. Righter  2  Second stronger. 
Los Gatos  F. H. McCullogh  1  Wife noticed a preliminary shaking. 
Los Gatos  I. H. Snyder  2  Partial intermission of 1 or 2 s. Second much stronger. 
Los Gatos  W. S. T. Smith  2  Interval was not sufficient to allow moving objects to come to rest. 
Skyland  T. Wightman  1 
New Almaden  J. F. Tathan  2  Second stronger. 
Wright  Mrs. A. L. Sears  1  Followed by tremors. 
Wright  Flora E. Beecher  2  About equal. 
Gilroy  W. J. Lawler  2  Second stronger. 
Sargent  W. B. Stuart  2  First stronger. 
Hollister  J. N. Thompson  2  Almost continuous; second did most damage. 
Tres Pinos  G. A. Waring  2 
Paicenes  G. A. Waring  1 
(4 miles SW.) 
Bear Valley  G. A. Waring  3  Noted by several people. 
Bitterwater  C. Z. Smith  2  Second stronger. 
Hernandez  E. M. Tucker  2  First part gentle, second more severe. 
Mt. Hamilton  H. K. Palmer  2  First harder; memory uncertain. 
Mt. Hamilton  A. M. Hobe  2  Jar. then pause, then tremble. 
Mt. Hamilton  W. W. Campbell  2  First harder. 
Calaveras Valley  R. Ingleson  2  2 separate shocks. 
Livermore  E. G. Still  2 
Danville  A. E. Clark  2  Second stronger. 
Mt. Eden  W. Gally  2  First sideways, second upward. 
Mills College  J. Keep  1 
Berkeley  A. C. Lawson  2  First prolonged, with secondary maxima; second brought down chimneys and ended rather abruptly. 
Bolinas  J. G. Peter  2  Second stronger. 
Farallones  J. A. Boyle  2  First stronger. 
Santa Cruz Range  M. Doyle  2  Tremor, then distinct shock; then violent shock, then tremor. 
Bellvale  Lilla E. Bell  2  Continuous shake with 2 heavy parts. 
Santa Cruz  G. A. Waring  2  Second stronger. 
Santa Cruz  O. J. Lincoln  2 
Delmas  Shock came suddenly, diminished, then at a second jolt the chimneys fell. 
Seabright  G. A. Waring  2 
Twin Lakes 
Bonnie Doon  T. R. Thayer  2  Second stronger. 
Soquel  Matilda Baker  2  First stronger. 
Ben Lomond  D. R. Guichard  2  Second stronger. 
Watsonville  E. McCabe  1 
Castroville  G. A. Waring  1  Felt as 1 continuous vibration. 
Prunedale  H. H. McIntyre  2  Second stronger. 
Salinas  Bertha M. Abbott  2  Second stronger. 
Monterey  N. W. James  2  First stronger. 
Chualar  G. P. Anderson  2 
Lonoak  J. Rist  1  Continuous shock, light at first; finishing with a hard stroke and twist. 
Shandon  C. J. Shaw  2 
― 376 ―
San Luis Obispo  S. D. Ballou  1 
San Luis Obispo  J. R. Williams  1  50 seconds long. 
San Luis Obispo  M. R. Venable  2  Slight tremor; then a second more severe; then a distinct oscillation, quite hard; then a tremor. 
Santa Maria  F. R. Schanck  3  First and second, 1 or 2 s.; third, 12 to 15 s. 
Pismo  Emma M. Patchett  2  Second stronger. 
Lompoc  A. McLean  1  One long shock. 
Lompoc  C. K. Studley  2  First gradually increased to maximum and gradually decreased. Second died suddenly. 
Santa Barbara  J. A. Dodge  1  About a minute long. 
Santa Barbara  S. F. Hunt  3  Second strongest. 
Los Angeles  W. D. Fuller  1 
Compton  L. A. Rockwell  2  First stronger. 
Azusa  A. P. Griffith  1  As if house had been struck by heavy blow. 
Toluca  W. C. Meddington  2 
Redding  L. F. Bassett  1 
Colusa  F. Roche  More than 1  Shock would die out, only to return again. 
Meridian  T. J. Taylor  2  Second stronger. 
Marysville  R. F. Watson  2  First lasted about 45 s.; the second about 90. 
Rumsey  J. M. Morrin  2  Second stronger. 
Guinda  J. Jacobsen  1  Continuous shake. 
Capay  S. Schwale  1  Continuous shake. 
Woodland  I. A. Morris  2  First stronger. 
Plainfield  H. O. Purington  2  First stronger. 
Black's Station  S. P. Cutler  2  First stronger. 
Knight's Landing  L. T. Shamp  2  First stronger. 
Sacramento  J. A. Marshal  2  Oscillation ended in 2 jars, with appreciable time between. 
Fairoaks  L. M. Shelton  1  One straight shake, very light. 
Main Prairie  Mrs. A. Rattike  1 
Binghamton  W. H. Smith  2  Second stronger. 
Collinsville  J. Antonini  4  Second stronger. 
Ione  J. F. Scott  2  Second stronger. 
Stockton  E. P. Higby  2  Of equal strength; interval of a few seconds. 
Oakdale  E. C. Crawford  3  Second stronger. 
Turlock  J. L. Brown  1 
Westley  W. G. Carey  2  Second stronger. 
Merced  F. J. Reidy  2  Second stronger. 
Madera  F. E. Smith  2  30 s. and 60 s.; second stronger. 
Fresno  J. P. Bolton  2  First stronger. 
Jameson  W. J. Williams  2 
Kingsbury  A. B. Loomis  1 
Riverdale  W. Lenson  2  Second stronger. 
Visalia  A. M. Doty  4  Last most pronounced. 
Exter  H. R. Stephens  2  Nearly equal in intensity. 
Bakersfield  A. G. Grant  1  10 seconds. 
McArthur  J. McArthur  2  First stronger. 
Susanville  J. Branham  1  Probably 2 s. 
Quincy  L. A. Barrett  1 
Kittle  F. Campbell  1 
Beckwith  J. W. Middleton  2  Not sure; there was a wavelike motion, with a sudden jar at the end. 
Boca  A. E. Daswell  1  60 s. 
Stirling City  H. B. Weaver  1 
Paradise  F. W. Day  2  Second stronger. 
Allegheny  W. A. Clayton  2 
Pino Grande  W. E. Basham  1 
Nashville  J. C. Heald  1 
West Point  J. A. Wilson  1 
Railroad Flat  E. Taylor  1 
Milton  J. H. Southwick  2  Second stronger. 
Tuolumne  J. T. Thompson  2 
Tuolumne  J. E. Coover  1 
LaGrange  J. A. Hammond  2  Second stronger. 
Sequoia  M. Crocker  2  2 prolonged light shocks. 
Darrah  R. Darrah  2  Second stronger. 
Fresno Flats  Postmaster  1 
Gold  T. J. Rhodes  2  Both about the same; quite heavy. 
Magnet  ?  1 
Mono Lake  E. A. Benedict  2  First stronger. 
Laws  G. D. Louderback  2  First gentle rocking; second small jerks. 
Lone Pine  G. D. Louderback  2  A few seconds apart. 
Lone Pine  G. F. Marsh  2  First stronger.