McLOUTH ON DUST SHOWER. 



16» 



On the basis of the average found the precipitation on a square mile 

 would be about six and one-third tons; on the total area as indicated 

 above the amount would be about ten thousand tons. 



I also weighed two residues which, though not affording accurate data,, 

 are significant. 



Mr. G. A. Rumsey, of Slocum, about twenty miles due east from Mus- 

 kegon, filled a common drinking glass with the snow and obtained there- 

 from a dry residue that weighed 0.29 grams. 



Ray Dawes, a pupil in Muskegon high school, collected a large panful- 

 of the snoAV found clinging to trunks of standing trees on the windward 

 side. This melted to three quarts of water and yielded sixty-five grams,, 

 approximate weight. 



The following notes are quoted from some of the correspondents tc 

 whom samples and inquiries were sent. 



C. E. Alberts* Ravenna. — "The dust almost spoiled the sleighing." 



L. L. Coates, Sparta. — ''There are several pounds of it (the dust) Id 

 my cistern." 



C. E. Ruthruff, Montague. — ''That deposited here was coarser than the- 

 sample you sent, and had a decidedly red color." (Statement not verified 

 by a specimen). 



Vernon G. Mayo, Newaygo. — "On an inclined walk usually ashed to 

 prevent slipping, it was abundantly deposited, so no ashes were needed.'^ 



D. E. Austin, Blue Lake Township, near Whitehall — "The sand or dust 

 storm was of seven or eight hours duration. * * * The dust coming in 

 swirls was deposited at right angles to the course of the storm, in some- 

 places scarcely a trace, then again sufficient to check the motion of a 

 sleigh. * * * In breaks of the snow storm the dust would appear like 

 great yellow smoke columns above the level of the main storm clouds." 



In physical form the dried material resembles flour. The particles,, 

 which are generally angular and irregular, range in diameter from .00& 

 to .00005 of an inch, few grains reaching the larger dimension. Its^ 

 color is a deep shade of yellow-orange. It sinks readily in water and i» 

 semi-pasty when wet. 



In composition the material is chiefly silica. About five per cent, ac- 

 cording to Mr. Orton, is organic matter, such as plant hairs, pieces of 

 wood fiber, desmids, etc. 



As is well known, dust storms are common in many parts of the world. 

 In Michigan they seem to be rare but are not unknown. Mr. L. L, 

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