Cresson.] ^04 [july 17^ 



f argentatus (Pack.), Proc. Ent. Soc, Phila., 3, 392 {StTienopis). 

 Massachusetts. 



Note. — This is perhaps the true H. argenteomaculatus, as separated by myself. 

 Harris first notices apply to an Eastern species. 



f Belirensii (Stretoli), Zyg. Bomb. N. A., 1, 105, PI. 4, fig. 6 {8t7ie- 

 nopis). California. 



f montanus (Stretcli), Zyg. Bomb. N. A., 1, 105, PI. 4, fig. 7 {Sthe- 

 nopis). California, (Sierra Nevada). 



hyperboreus Mosch., W. E. M., 6, 129 (Epialus), Taf. 1, fig. 1 ; Hep. 

 pulcher Grote, Proc. Ent. Soc, Phila., 3, p. 522, PI. 5, fig. 3. Labrador; 

 Colorado Territory. 



t Labradoriensis Pack., Proc. Ent. Soc, Phila., 3, p. 394. Labra- 

 dor. 



t mustelinus Pack., Proc. Ent. Soc, Phila., 3, 393. Eastern States. 



gracilis Grote, Proc. Ent. Soc, Phila., 3, p. 522, PI. 5, fig. 4. Quebec 



\ Californicus Boisd., Ann. Soc. Ent. Belg. , 12, p. 85. California. 



f heetoides Boisd., Ann. Soc Ent. Belg., 12, p. 85. California. 



KESULTS OF AN EXAMINATION OF AN EXPLODED LOCO- 

 MOTIVE BOILER, AND OF EXPERIMENTS TO 

 ASCERTAIN THE CAUSES OF EXPLOSION. 



By Dr. Charles M. Crepson. 



{Bead before the American PMlosopMcal Society, July 11, 1874.) 



The boiler was constructed of No. 1 {^^) boiler iron, single riveted (with 

 the exception of the junction of the waist with the fire-box, which was 

 double riveted) ; it was of the ordinary locomotive form with enlarged 

 grate surface adapting it for use with Anthracite fuel. 



The fire-box had the ordinary flat crown sheet suspended from wrought 

 iron girders by means of bolts | in. in diameter, placed 4| in. apart, the 

 ends of the girders being supported upon the vertical sides of the fire-box. 

 The vertical sheets of the fire-box were stayed by wrought iron bolts 

 I in. in diameter, placed 4 in. apart, screwed into the sheets and riveted 

 at the end. 



The crown sheet and that part of the boiler directly over the fire-box 

 were connected by stay-rods. 



The engine had been run upon a siding to pull out a train of cars, 

 which train being heavier than was ordinarily pulled, the steam-blower 

 was applied for the purpose of increasing the intensity of the fire and 

 generating steam of a higher pressui-e than was usually employed. But 

 when preparations for starting were completed, it was found, upon refer- 



