A BUREAU OF SCIENTIFIC INFORMATION. 409 



cal ends thereof and moves forward and upwardly through the vertical flasks and 

 the intermediate drum to the main steam drum, thence rearwardly therein and 

 downward to the mud-drum, at which point a considerable quantity of the impur- 

 ities of the water are deposited, and may be removed, as convenient. 



In setting this boiler for steam-heating purposes the walls of the furnace are 

 constructed with an annular air space, within which project suitable deflecting- 

 plates built in the walls for the purpose of detaining the upwardly moving heated 

 air. This latter is admitted through openings near the floor, and controlled by 

 registers situated above the furnace, from which point, after being heated by con- 

 tact with the walls of the furnace, it is conducted to the room above the boiler, as 

 desired. 



The inventor is Mr. J. E. Lewis, of Bowdoin Centre, Maine. 



A BUREAU OF SCIENTIFIC INFORMATION. 



With a view towards the more general dissemination of the results of scien- 

 tific investigation, and of facilitating the work of the student in natural history, 

 the following members and officers of the Academy of Natural Sciences have 

 associated themselves into a Bureau of Scientific Information, whose function 

 shall be the imparting, through correspondence, of precise and definite informa- 

 tion bearing upon the different branches of the natural sciences. It is believed 

 that through an organization of this kind considerable assistance can be rendered 

 to those who, by the nature of their environs, are precluded from the advantages 

 to be derived from museums and libraries. 



As the organization is of a purely voluntary character, it is to be hoped that 

 no unnecessary burden will be imposed upon its members by communications of 

 an essentially trivial nature. All correspondence must be accompanied by a re- 

 turn stamp (two cents). 



. Joseph Leidy, M. D., Mycetozoa; Rhizopoda; Entozoa ; Vertebrate Paleon- 

 tology, Professor of Anatomy, University of Pennsylvania; President Academy 

 Natural Sciences, Edward Potts, Pond Life ; Fresh-water Sponges and Bryozoa. 

 George W. Tryon, Jr., Conchology, Conservator Conchological Collections, Aca- 

 demy Natural Sciences. Benjamin Sharp, M. D., Worms; Annelids; Histology, 

 Professor Invertebrate Zoology, Academy Natural Sciences. G. H. Horn, M. 

 D., North American Coleoptera, President American Entomological Society; 

 Corresponding Secretary Academy Natural Sciences. H. C. McCook, D. D., 

 Ants; Spiders; Insect Architecture, Vice President Academy Natural Sciences. 

 Henry Skinner, M. D., North American Moths, Conservator of Lepidoptera, 

 American Entomological Society. Eugene M. Aaron, Diurnal Lepidoptera, 

 Editor.of Papilio ; Cvi^tod.\3.x\ Entomological Section, Academy of Natural Sciences. 

 W. N, Lockington, Echinoderms; Fishes. Spencer Trotter, M. D., North Amer- 

 ican Ornithology. Thomas Meehan, Exotic and Cultivated Plants, Vice-Presi- 

 dent Academy Natural Sciences ; State Botanist, Pennsylvania. J. H. Redfield, 



