DEPARTMENT OF GEOLOGY. 2G7 



In tlie wall cases occupied by the geograpliic series of econouiic ma- 

 terials, it has been found advisable to largely do away with the loose 

 blocks and substitute in x^lace of them narrow shelves of an equal 

 thickness, but raised by brackets a few inches above the lower, wider 

 shelf. This allows a little variation in the size of specimens on the 

 lower shelf, and permits the placing- of the label directly against the 

 edge of the narrow shelf itself, where it is not obscured by the speci- 

 men in front and can be readily seen. 



How to so mark a specimen that its identity can under no ordinary 

 circumstances beconu^ destroyed has ever been a source o"f trouble to 

 those engaged in uuiseum work. After considerable experimenting, 

 the method of procedure given below has been adopted. 



As soon as the specimen is catalogued, a blue rectangular stripe of 

 sufficient dimensions for receiving the number is ])ainted upon it in oil 

 colors, the material used being dry ultramarine l)lue mixed m itli white 

 lead and sufficient hard (til tinish to thin it for applying with a biush. 

 This dries quickly, giving a liini, glossy surface, upon which the cata- 

 logue numlter is then painted in white, Windsor and Newton's flake- 

 white tube i)aint, thinned with turi>entine, having l)een Ibund best 

 adapted for this purpose. This gives a practically indestructible num- 

 ber, sufficiently conspicuous to be readily found on specimens of any color 

 or texture, and which at the same time does not, if neatly applied, in the 

 least mar their appearance. This method is of course applicable only 

 to substances of considerable firmness of texture. Pulverulent or 

 liquid materials mnst be marked u])on the box, bottle, or tray in which 

 tliey are exhibited. 



1 may say, further, that the use of the maroon color for background 

 and shelves has, so far as the curator is concerned, been condemned 

 and the practice discontinued. This for the doubh^ reason that the 

 color is too dark an<l gives rise to too nuich reflection from the glass 

 doors of the cases, and that it is too easily' soiled. The coh)r found to 

 be most serviceable and generally satisfactory is light, with a faint 

 tinge of yellow or cream, the specimens tlieniselves being ])laced on 

 blocks painted a dull, lusterless black. 



Owing to the jn'essure of routine work no time has l)een given to 

 research with a view to immediate publication. The titles of such 

 l)apers as have so far appeared are given in the bibliography (section 

 IV). As will be observed, this includes, with two exceptions, merely 

 matter furnished to one of the industrial journals. 



The collections have been frequently consulted by others not officially 

 connected with the Museum, and in three instances material have been 

 lent for study. 



In this way a portion of the collections of the Fortieth Parallel Survey 

 were lent to Mr. C. R. Van Hise, a small series of Arkansas syenites 

 to the Geological Survey of that State, and some fifty specimens of 

 Mesozoic eruptives to Prof. 11. D. Campbell, of the Washington and 



