April 14, 1905.] 



SCIENCE. 



587 



above the river and about thirty-five miles by 

 trail west of Dedrick. The journey hither 

 across and through the caiion has revealed a 

 remarkable physiographic and geologic story 

 which the party considers well worth the hard- 

 ships of the journey and which will be made 

 the subject of special papers. The region is 

 full of archeological interest, too, through the 

 ruins of cliff dwellers and other prehistoric 

 peoples. In the Rio Chico branch of this 

 canon there is a set embracing thirty-seven 

 houses. 



From Guaynopita our course lies southward 

 through the complex of canons tributary to 

 the great canon of the Yaqui and out on to 

 the plateau as far as Ocampo, where the fa- 

 mous ancient mine of Jesus Maria is located. 

 Thence we turn back to Minaca and there 

 begin the long railway journey to New York. 



Edmund Otis Hovey. 



the metric system again. 



To THE Editor of Science: For the benefit 

 of those who are clamoring for the adoption 

 of the metric system, I desire to give an il- 

 lustration of the beautiful simplicity of the 

 system of units in vogue in the United States 

 and Great Britain. Any of our units of 

 measurement would answer the purpose, for 

 they all partake of the same delightful elas- 

 ticity of value. Let us take the collection of 

 units of measure commonly denominated the 

 gallon. In order that we may comprehend 

 the relation of these various units to each 

 other it is desirable to have some fixed unit 

 as a means of comparison. As the cubic inch 

 in use in America is not the same as that of 

 Great Britain, and as it is desirable to use 

 some unit of capacity that has only one value, 

 we shall be compelled, much against our 

 wishes, to use the liter as a unit in which to 

 express the volume of the various members of 

 the gallon family. 



Gallon No. J.— 3.78543 liters. This gallon 

 is variously denominated in the literature of 

 metrology as the liquid (metric), liquid (na- 

 tional), metric (U. S.), Winchester, wine, and 

 dry (metric). It is said to contain 231 Amer- 

 ican cubic inches. It is stated also that this 

 gallon is generally used by American hydraulic 



engineers. It is a little difficult to be certain 

 on this point, however, for many authors fail 

 to state the volume of the gallon they use, in 

 liters, and do not state whether American or 

 British inches are meant. 



Galloji No. 2.-~A.A070 liters. This is the 

 dry (national), or dry (TJ. S., or Br.), accord- 

 ing to the Standard Dictionary. It is sup- 

 posed to be used a good deal by tradesmen, 

 and is sometimes referred to as a half peck^ 

 Whether it is used in England is a little diffi- 

 cult to ascertain, because of failure of writers 

 to mention its volume in any fixed unit. 



Gallon No. 5.-4.54346 liters. British (Men- 

 denhall), liquid (U. S., or Br.), or Imperial 

 gallon. 



Gallon No. Jf. — 4.-6209 liters. Legal standard 

 dry gallon in Wisconsin and Connecticut; 

 legal standard for ale, beer and milk in New 

 Hampshire and Minnesota. Used in these 

 states by tradesmen in buying these commodi- 

 ties. Also a legal standard in Maine. 



Gallon No. 5.—' Proof ' gallon. " This has 

 the volume of a wine gallon containing one 

 half its volume of nearly pure alcohol at 60° 

 F." The number of proof gallons in a quan- 

 tity of distilled liquor is found by multiplying 

 the per cent, of proof (= twice the per cent, 

 of alcohol present) by the number of wine 

 gallons. Used by gangers in assessing in- 

 ternal revenue tax on spirits. 



I have not taken the time to verify all the 

 references in parentheses above. Indeed, I 

 was unable to do so with the ordinary ref- 

 erence books available to the student. It 

 seemed, too, that in treating so simple and 

 easily understood a subject, that it might be 

 well to content myself with the above refer- 

 ences, in order to show how simple the whole 

 matter is, and what a delightful and satisfac- 

 tory system we have, especially when exact 

 measurements are needed. It is also probable 

 that the careful reader will be stimulated by 

 this hurried and incomplete account to in- 

 vestigate the subject further. 



W. J". Spillman. 



NEW AMERICAN OSTRACODA. 



To THE Editor of Science: In collections 

 of ostracod crustaceans made near Greeley^ 



