The Arkansaw traveler., 1885-02-21
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 SCIENTIFIC MISCELLANY.

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 SCIENTIFIC MISCELLANY. The artificial heat of London has hee,
 estimated sufficient to raise the temperatuY.
 of an air stratum 100 feet thick over the .n.
 tire city two and one-hah degrees eyerv hon,
 An English writer points out the prob.
 ability that smoky atmosphere is not '.
 wholly uomitigated evil, since it's carbon and
 sulphur must absorb many germs of disease
 and tend to prevent the spread of epidemics
 A large amount of oil exists in the
 stormy petrel, and when fat, according to
 brunnich, the inhabitants of the Faro.
 Islands use it as lamp, obtaining their lisb,
 from wick drawn through the birds body,
 On keeping fatty oils several hours at 4 temperature of four degrees below zero, Serra Carpi has obtained solids of remarka-
 ply different degrees of hardness. A minute cylinder of iron was oaly forced into soiidi
 ned olive oil by pressure Of I,7oo grams. wAile cotton oil required but az grams.
 The oldest geographical society has been generally regarded as that of Paris, but according to Dr. Ruge that honor belopgs to the Cosmographic society of Nurenbere. It was established about 1z4o, while the pari. society was not founded until 1sar. A Svi,s geographer estimates that the worlds geo graphical societies now contain ss,ooo mem. bers.
 A Powerful Apparatus.-The lar gest electrical influence machine in the world has just been made for the physical laboratory at South Kensington. Its discs are seven feet in diane CT, of Plate-glass three-eighths of an inch thick, and weigh aso pounds each. Tested under unfavorable conditions, the machine has given a constant stream of sparks fourteen inches long.
 Early Birds.-Prof. Huxley has re- marked that while birds now constitute a well defined group, nobody mistaking the forms included therein, we find the case to be different when we turn to the geological record. Fossil forms are found that present definitions do not embrace, indicating a wider range of structure, and the existence of types intermediate between birds and reptiles.
 Inequalities Sea Level.-A study and comparison of the ocean temperature re- cords of the Challenger exploring expedition have shown Dr. James Crell that the surface of. the Atlantic must be lower at the equator than farther north, the maximum height of the north Atlantic being reached between the fortieth and fftieth degrees of latitude. This difference is due to the difference in the specific gravity of the water. In the latitude of Havana the Atlantic's surface must be two and one-fourth feet higher than at the equator. and ia that of Chesapeake Bay the difference is foot greater.
 An Interesting Celestial Visitor.- Encke's comet, which travels around the sun in about three and half years without going beyond the boundaries of the solar system. aud which has the honor of being the first known comet Of short period, is chiefly re- markable on account of the retardation of its motion. This has amounted to about four days since 1879, and is supposed by some astronomers to prove the existence of a resisting medium in space. The date of the comets perihelioa passage this year is March 7th, and its return was first observed December I3th. It is visible only with a telescope.
 The Ears Capacity.-Ith has been found by Dr. Lawson Tsit that as rule. the ear in women can perceive higher notes--that is, sounds with a greater number of vibrations highest limit of and ability for the human ear is somewhere between 4r,ooo and 4a 900 The ears of most persons seem to be uncqually sensitive to acute sounds. the right ear usually hearing a higher note than the left. To show the ear's range. it may be added that very low notes of about fifteen vibrations per second may be per- ceived, but when the vibrations become a little slower they cease to produce the effec. of continuous sound, and each gives a sep parate impression upon the ear.
 A Microscopes "Field."-Great as are the wonders the microscope reveals, it will not-as is sometimes supposed-show a fy magniied to the size of an elephant. nor aea of horse-like proportions, for the reason hat under high power only q very small part of either of these creatures can be seen 1t one time. The size of the field of view covered by ordinary lenses has been com puted as follows: With . power of az about one fourth of an inch with % diameters, one eighth of an inch; with 100 iiameters, one-sixteenth of an inch; with ;oo diameters, one-eightieth of an inch; and with 1000 diameters, one one-hundred iftieth 'f an inch, space ordinarily invisible to the naked eye. Even the smallest creature shown Q our unaided vision, therefore, cannot be 'een entire when magni6ed 1000 diameter.