28 



SCIENCE 



[N. S. Vol. XXVII. No. 679 



and adjoining side, shows where a considerable 

 piece, weighing perhaps two pounds, was 

 broken off, antecedent to its burial, probably at 

 the time it fell. Two of the projections on 

 one side are flattened, as if by pounding, but 

 closer examination shows fine strise running 

 evenly across both surfaces, which are in the 

 same plain and partly join each other, sug- 

 gesting that the meteorite in falling may have 

 glanced on a rock, making a slickensided sur- 

 face. The meteorite also shows two marks 

 made by a sharp tool, like an ax, which also 

 apparently antedate its last burial in the sand. 

 But the most marked feature about this iron 

 is the presence, on the surface, in a number of 

 places, of bright unaltered triolites with a part 

 of a crystal face showing in one place. This 

 feature, in connection with the general fresh- 

 ness of the iron and the presence of what 

 seems to be the original surface over a good 

 part of it, indicates that it is a comparatively 

 recent fall. 



WilUamsiown Meteorite.- — I secured this 

 siderite last March from Mr. A. E. Ashcraft, 

 who found it April 25, 1892, on his farm in 

 Grant County, Ky., three miles north of Wil- 

 liamstown. It is a nearly square, thin, flat- 

 shaped iron about 16 X 12 X 2i inches thick in 

 the center, thinning to a blunt edge at either 

 end. It was entire when it reached me, with 

 the exception of a few ounces broken from one 

 edge, and weighed 68 pounds (30.85 kilo.) 

 and has a specific gravity of 8.1. It has 

 already been cut into a number of sections, 

 which etch very readily, showing the structure 

 to be tliat of a Mediam octohedrite. Three 

 distinct systems of Kamacite lands are cut at 

 approximately right angles, while a third is 

 cut at an angle of 60° or 70°, thus showing an 

 apparent breadth of about three times that of 

 the other- lands. Triolite seems to be pretty 

 generally distributed throughout the mass in 

 very small grains, although two nodules about 

 one half inch in diameter were revealed, but 

 the total amount of this mineral is small, as 

 might have been inferred from the general 

 smoothness of the surface, and the specific 

 gravity. 



A fuller description of both of these meteor- 

 ites will be given when the analysis, which 



will be made at the National Museum, is com- 

 pleted. 



Edwin E. Howell 

 Washhstoton, D. C, 

 September 17, 1907 



DR. ARMSBY's new UNIT FOR ENERGY 



In a paper read before the Society for 

 the Promotion of Agricultural Science' Dr. 

 Armsby suggests a new unit for energy. This 

 unit is a million gram-calories and he calls it 

 a Therm — spelled with a capital T. Since the 

 word therm has been suggested and occasion- 

 ally used to mean the gram-calorie, and since 

 we are accustomed to use the prefixes hilo and 

 mega to denote, respectively, a thousand and a 

 million — as in kilometer, kilogram, kilowatt, 

 raegadyne, megohm — ^would it not conform 

 better to our customary nomenclature to call 

 the kilogram-calorie a kilocalorie and a thou- 

 sand kilogram-calories a megacalorie? These 

 names have the advantage that they would at 

 once be understood by a man who had never 

 seen them before, whereas the name Therm 

 would for a time need explanation. 



A. T. Jones 



Purdue University 



SPECIAL ARTICLES 



SOME LIFE-HISTORY NOTES ON MEGARHINUS SEP- 



TENTRIONALIS" D. AND K. 



Some observations upon the life history of 

 this rather rare and beautiful species of mos- 

 quito were made at this station' during the 

 past season. 



On September 10, 1906, the senior author 

 collected 24 larvae of this species and several 

 of a smaller species, probably Culex pipiens, 

 from a half-barrel tub of rain water, not more 

 than 100 feet from an inhabited dwelling, on 

 a farm near Church Hill, Tenn. All were 

 placed in a small pail together and carried 

 overland twenty-three miles in a buggy and 

 then forty on the train to this laboratory, 



1 Science, Vol. XXVI., p. 670. 



- Smithsonian Miscellaneous Collectiono, Vol. 

 48, Part 3, No. 1657. 



' Tennessee Agricultural Experiment Station, 

 Knoxville. 



