388 



REPORT OK NATIONAL MUSEUM, 1!)03. 



in the l^ostoM iimsoinn incntioiicd, unless it eseaped my notice, while 

 scarce!}^ a building- for collections exists which is not capable of 

 improv^ement in this respect. The company makes (JO different kinds 

 of pi'isniatic panes and single prisms, the latter for skylights, wdiich in 

 the United States arc used very nuich in rooms under the pavements 

 of the streets, since these rooms belong to the cellars of the adjacent 

 houses. The ribbed panes, of the uniform size of 10 square centi- 

 meters, are electrol^^ticall}^ glazed between liat copper bands," and are 

 then fireproof, which offers another great advantage and permits their 

 employment as window shutters, doors, etc., for closing- entire stories, 

 and the like. 



A similar company is the Mississippi Glass Company, with agencies 

 in Boston (Boston Plate and AVindow (llass Company). Prof. C. IT. 

 Norton, of the Massachusetts Institute of Technology, made a report 

 on this subject in 1898. based upon experiments (The Diffusion of 



Fii.. js.— TriMnatic, ribbed-glass unit of the 

 American Luxfer Prism Company. 



-Single prism, as made by the Americau 

 Luxfer Prism Company. 



Light through Windows, in the seventy-second circular of the Boston 

 Manufacturers' Mutual Fire Insurance Company, b}^ E. Atkinson, 18 

 pages in quarto).'' O. K. Basquin })ublished in lSi>9 for the German 

 Luxfer Prism Syndicate in Berlin a Handbook on Luxfer Prisms and 

 Electro-glass (82 pages, quarto, wath 21 plates and al)out 100 text 

 figures), which offers an explanation of this subject, which is so 

 important for lighting and such a security against fire.'^^ I give :i 



« There are now (1903) manufactured large panes of prisniatically ribl)e(l glas.s with- 

 out the.«e copper bands between, which, though not as powerful as those small ones, 

 give very good results (as I experienced in the Dresden Museum), and which are 

 much cheaper. 



&This appeared in 1902 in third enlarged edition, in Report III of the Insurance 

 Engineer Experiment Station, 31 Milk street, Boston, i)ages 10-33, with many 

 illustrations, quarto. 



c Dr. B. WandoUeck, assistant in the Dresden Zoological INIuseum, was kind enough 

 to prepare the following statement concerning luxfer prisms and electro-glass, based 

 on the two papers cited in the text as well as on his OM'n studies. I insert it here 



