May io, 1889.] 



SCIENCE. 



357 



bushing is reamed out, and forced steam-tight into its bored seat. This 

 form of construction has many advantages. The casting is greatly 

 simplified, avoiding all chances of porousness, sand-holes, and other 

 defects which are liable to cause concealed leaks. The valve-seat 

 can be made perfect, and the parts registered exactly, on which 

 latter fact depends the perfection of the steam-distribution, and the 

 consequent economy of the engine ; and, lastly, the valve-seat can 

 be easily and cheaply renewed when worn. 



The valve-chest also contains a small by-pass valve controlling 

 a cored passage, by which live steam can be admitted to the low- 

 pressure cylinder, to turn the engine over ite centre when starting. 

 The steam and exhaust connections are on the side of the valve- 

 chest towards the back of the engine, bringing the throttle-valve 



der out upon a table, and examining it carefully, two adult beetles 

 of Tenebrioides niatcritanica were found dead in the burrows in 

 the powder. How long these beetles had remained in the powder 

 alive, it is obviously impossible to state ; but it would be safe to 

 say that they entered it from motives of choice, and either subsisted 

 upon it, or else did an incredible amount of tunnelling without sus- 

 tenance. While at the time the beetles were removed from the 

 powder the latter was not fresh, and did not retain its full strength, 

 there still remained enough to impart a tingling, burning sensation 

 to the nostrils when any of the powder was inhaled through the 

 nose, yet not enough to set one to sneezing. 



— In Germany, for some years past, according to ihe Journal of 

 the Society of Arts, London, efforts have been made, and with 



WESllM(n)LSE CJMPOUND ENGINE, LONGITUDINAL sl(I|i)\ 



into convenient position, and admitting of the ready removal of the 

 valve-chest when desired. 



NOTES AND NEWS. 



F. IVI. Webster, Purdue University, La Fayette, Ind., in a let- 

 ter to the United States Entomological Bureau, Dec. 23, 1S87, 

 states that some two or three years previous samples of various 

 substances used for insecticides were placed in the Agricultural 

 Museum of Purdue University, at La Fayette, Ind. As the object 

 was merely to display the substances, they were placed in glass 

 flasks, such as are used for similar displays of seeds, the mouth be- 

 ing in the base when the flask is in an upright position. One of 

 these flasks contained several ounces of powdered white hellebore, 

 which, as it was never disturbed, had settled into a somewhat com- 

 pact body. On removing this flask a few days later, the cork stop- 

 per was found to have been burrowed through, evidently from 

 without, and the mass of powder was literally full of burrows and 

 channels passing through it in all directions. On turning the pow- 



considerable success, to acclimatize the oak silkworms of China 

 and Japan {Aiiacus Pernyi axiA Attacus Yajna-maz). They have 

 been raised in the open air, protected from the attacks of birds by 

 nets of gauze or wire, changed from place to place as the oak- 

 leaves are consumed. Late frosts and excessively dry weather 

 have been injurious in depriving the worms of food. In California 

 a new wild silk-moth, before unknown, has been found thriving on 

 the poisonous species of Rhamniis Californicus or R. Ptirshianus. 

 It produces a silk as good as that of the domesticated Bovibyx. 

 Owing to the favorable nature of the climate, without the frosts or 

 rains of China and Japan, great hopes are obtained of propagating 

 this species. In Yucatan a wild moth has also been met with, 

 somewhat allied to the mulberry-worm, which produces silk of a 

 bluish tint ; but the gum which envelops it is difficult to remove. 

 Mr. John Maclntyre, a recent traveller in Manchuria, records havmg 

 met with several new species of silkworm, which he describes in the 

 Chinese Times. One wild worm feeds on the Pinus chinensis. 

 It forms handsome cocoons, which yield a strong silk ; but they 

 are so mixed up with the needle-like leaves of the pine, that the 



