xlv 



The Secretary read a communication from Dr. Gustavus Hin- 

 richs, from Iowa City, containing a brief preliminary note on the 

 remarkable meteor of the afternoon of May 5th, and the meteor- 

 ites which it has scattered over the central part of Winnebago 

 county, north-west of Forest City, Iowa. "The meteor was 

 so bright that it was distinctly seen from Des Moines, over one 

 hundred miles south of its termination. Its cosmical flight came 

 to an end in a tremendous detonation at an elevation of about ten 

 miles ; a cloud formed by the detonation remained stationary at 

 this point for some time. Thus far a multitude of small meteors 

 have been found scattered over more than a dozen square miles 

 of Winnebago county. Most of this meteorite field is unbroken 

 prairie land, which fact has interfered with the finding of speci- 

 mens. The search has been very active, since the specimens are 

 readily sold at $1 an ounce. Few of the specimens weigh over 

 a pound ; the largest one thus far foimd is a splendid specimen 

 66 pounds in weight and compietely coated black. [Photograph 

 enclosed.] 



The meteorites of this kind are Chondrites [Rose] and Spo- 

 radosideres [Meunier] containing the nickelferous iron in small 

 particles only, so far as we have been able to see. The specific 

 gravity of a small perfect specimen was found to be 3.65. [Spe- 

 cimens of eleven grammes enclosed.]" 



'June 2d, 1890. 



President Nipher in the chair ; eleven members present. 



Mr. Letterman offered to make a donation to the Academy of 

 the duplicates of the specimens in his herbarium, which he is just 

 revising. He was requested to make his offer in writing, and 

 the matter was then referred to the Council. 



Mr. Nipher made some remarks on the efficiency of an elec- 

 tric-lighting plant. He showed how the indicated horse-power 

 varied with the number of lamps, and how insufficient wiring of 

 a building would affect the indicated horse-power as a function of 

 the number of lamps. 



The Secretary read, by title, a paper on "Analysis of the Bari- 

 um Group," by Dr. C. Liideking. 



