CORRESP ONDENCE. 



263 



A SHOWER OF DUST. 



Messrs. Editors. 



In your July issue, I find a communica- 

 tion from Mr. Kirkwood, of Bloomington, 

 Indiana, in regard to a deposit of dust that 

 was observed there on tlic 28th March, 1880, 

 and in which the theory is advanced, to ac- 

 count for its origin, that, since a similar 

 phenomenon occurred in Europe almost si- 

 multaneously, both may be of common ori- 

 gin.* 



The following is collated from the 

 " Weather Review " (the official organ of 

 the United States Signal Service) for March, 

 1880, and it undoubtedly leads us to infer 

 that the Bloomington phenomenon and those 

 treated in the " Review " were identical : 



No. XV. This area appeared in British 

 Columbia, the afternoon of the 24th ; Port- 

 land barometer 0-46, and Fort Benton ba- 

 rometer 0-45 below the normal. Moving 

 southeastward, it was in Idaho the morning 

 of the 25th, and by an easterly path was 

 central in Nebraska the afternoon of the 

 2t5th, Omaha barometer O'ZS below the 

 normal ; at that time the pressure in the en- 

 tire Missouri and upper Mississippi Valleys 

 ranged from 0-40 to 0-75 below the normal. 

 At midnight the area was central in Iowa, at 

 which time the pressure over the greater 

 part of the lower Missouri and upper Mis- 

 sissippi Valleys was 0-60 below the normal. 

 At that time brisk easterly winds prevailed 

 in the entire lake-region and Mississippi 

 Valley generally, accompanied by rain, and 

 brisk northerly winds from the Missouri 

 Valley westward. On the morning of the 

 27th the area was central in eastern Iowa 

 Davenport barometer 1'04 below the normal 

 in the afternoon in northern Illinois, and 

 at midnight in northwestern Ohio. During 

 the day violent wind-storms (see data re- 

 garding local storms) occurred in the upper 

 Mississippi and lower Missouri Valleys, and 

 in the upper lake-region, westward from the 

 Mississippi Valley to the Rocky Mountain 

 slope, but little or no rain falling ; remarka- 

 ble dust-storms prevailed. Las Cruces, New 

 Mexico, 26th, very violent sand-storm, fill- 

 ing the air with dust. Leavenworth, Kan- 

 sis, 27th, blinding dust-storm, almost ob- 

 scuring the sun at 10 a. m. Fort Davis, 

 Texas, violent sand-storm. Ringgold, Ohio, 

 27th, heavy wind and hail storm. Professor 

 Nipher, of St. Louis, Slissouri, reports this 

 storm " as the most remarkable phenom- 

 enon of the month. It covered the entire 

 State, except the extreme southern part. 

 The atmosphere was filled, during the whole 

 day, with a fine grayish dust, which, in the 

 western part of the State and in eastern 

 Konsas, was so dense as to obscure the lisht 

 of the sun, and to render objects invisible 



at a distance of from one to three hundred 

 yards. The wind was very high, coming in 

 most cases from the west and northwest." 



P. F. Lyons. 

 Leavenworth, Kansas, July 28, 1880. 



* In our opinion. Professor Kirkwood's letter 

 will not bear this construction. Ed. 



MR. HERBERT SPENCER'S PACTS. 

 Messrs. Editors. 



Allow me to say, respectfully, that Mr. 

 Spencer impairs the public confidence in his 

 conclusions by inattention to the reliability 

 of what he states as facts. It is not enough 

 that an author can cite book and page of 

 some other writer in exact confirmation of 

 his words. Responsibility for the truthful- 

 ness of the statement, which is the main 

 thing, must rest upon him who repeats as 

 well as on him who first puts it forth. A 

 teacher of philosophy, especially, is bound to 

 acquire a critical knowledge of the facts he 

 uses, and to employ this knowledge judi- 

 ciously for the benefit of those he attempts 

 to instruct. In Mr. Spencer's preliminary 

 article upon " Political Institutions," in the 

 October number of "The Popular Science 

 Monthly," the following statement occurs at 

 page 6 : " Having great cities of one hun- 

 dred and eighty thousand houses, the Mexi- 

 cans had also cannibal gods ; . . . and, with 

 skill to build stately temples big enough for 

 ten thousand men to dance in their courts, 

 there went the immolation of twenty-five 

 hundred persons annually, in Mexico and 

 adjacent towns alone, and of a far greater 

 number throughout the country at large." 



A few words concerning the one hun- 

 dred cuul eighty thousand houses in the pue- 

 bh, not the city of Mexico. There is some 

 difference in tlie estimates of the population 

 of Mexico found in the Spanish histories, 

 but several of them concurred in the number 

 of houses, which, strange to say, is placed at 

 sixti/ thousand. Zuazo, who visited Mexico 

 in 1726, wrote " sixty thousand inhabitants," 

 not houses ( Prescott, " Conquest of Mcs.- 

 ico," vol. ii, p. 112, note); the anonymous 

 conqueror, who accompanied Cortes, says 

 "sixty thousand inhabitants" " soixiatite 

 mille habitans " [A.. Tarnaux-Campans, vol. 

 X, p. 92) ; but Gomara and Martyr wrote 

 "sixty thousand houses," and this esti- 

 mate has been adopted by Clavigero 

 (" History of Mexico," Cullen's translation, 

 vol. ii, p. 3fi0) ; by Horrera (" History of 

 America," London edition, 1725, Stevens's 

 translation, vol. ii, p. 360), and by Prescott 

 (" Conquest of Mexico, vol. ii, p. 112). Solis 

 says "sixty thousand families," instead of 

 houses or inhabitants (" History of the Con- 

 quest of Mexico," London edhion, 1738, 

 Townsend's translation, vol. i, p. 393). This 

 guess would give a population of three hun- 

 dred thousand, although London at that 

 same time, after centuries of growth, con- 

 tained but one hundred and fortv-five thou- 



