EEPORT OP NATIONAL MUSEUM, 1915. 59 



Dr. Merrill also prepared and submitted for publication an illus- 

 trated handbook and catalogue of the meteorite collection in the Na- 

 tional Museum, in which an attempt has been made to include de- 

 scriptive matter of value to the student, although presented in such 

 a way as to make it of interest to the general xDublic. A second line 

 of research, one of economic importance and mentioned in the last 

 report, had for its object the determination of the relative solubility 

 in water charged with carbonic acid of some of the most widely used 

 limestones and marbles. Seventy-five samples, including nearly half 

 as many varieties, were tested for periods varying from 70 to 90 

 days, and the conclusions prepared for publication. 



As in previous years, Dr. Merrill was called upon on several 

 occasions for expert advice as to the quality of stone submitted for 

 the construction of Government buildings or of buildings to be 

 erected under Government supervision. The Lincoln Memorial and 

 the Eed Cross Building were the principal structures to which his 

 attention was asked during last year. 



Mineralogy and petrology. — The most important accession of the 

 year was a bequest from the late Brig. Gen. William H. Forwood, 

 U. S. Army, comprising several hundred specimens of minerals and 

 cut stones, of greatest interest being a suite of unique titanite crystals 

 from an exhausted locality at Bridgewater, Delaware County, Pa. 

 The Geological Survey transferred various lots of gem minerals, in 

 both rough and cut form, selected especially for exhibition by Mr. D. 

 B. Sterrett, honorary custodian of gems and precious stones, and 

 including 4 specimens of turquoise, figured in Dr. J. E. Pogue's 

 monograph on this mineral, recently published by the National 

 Academy of Sciences. Additional sf)ecimens from the Survey are 

 also of exceptional value, consisting for the most part of types of 

 new species or restudied and redescribed material from new lo- 

 calities. Among them are a large mass of shattuckite and bis- 

 beeite (new species) from Bisbee, Ariz.; a large crystal of colum- 

 bite, variety manganotantalite, from San Diego County, Cal. ; cus- 

 terite (new species) from Idaho; cebollite (new species) and an 

 unusually large cleavage specimen of melilite recently discovered in 

 Colorado; the rare mercury minerals montroydite, eglestonite, 

 kleinite, terlmguite and calomel, from Terlingua district, Tex ; vari- 

 scite and lucinite (new species) from Lucin, Utah; ferberite crystals 

 from Colorado ; struverite from South Dakota ; neptunite from Cali- 

 fornia; fremontite (new species) from Canon City, Colo.; and 

 vesuvianite, bournonite and prehnite from new localities. 



Col. Washington A. Koebling, of Trenton, N. J., contributed one 

 of the largest known nuggets of osmiridium, weighing 40 grams; 

 Mr. Clarence S. Bement, of Philadelphia, Pa., two large crystals of 



