20 



SCIENCE. 



[Vol. XVI. No. 388 



in Cleveland and Canton, and is present in many parts of Colum- 

 bus. It probably occurs, also, in a large number of other cities 

 and towns of the State. The presence of the pests is shown by 

 the occurrence upon the twigs of maple-trees, especially on tlie 

 under side, of a brown, circular, leathery scale about one-quarter 

 of an inch in diameter, beneath which is a fluffy, cottony mass, 

 that at this time is alive with hundreds of young lice, appearing 

 to the unaided eye as minute white specks moving about. About 

 six years ago there was a similar outbreak of this insect in Ohio, 

 Illinois. Michigan, and adjacent States, when many trees were 

 rendered unsightly and filthy by the presence of the lice, and 

 some were killed by the attack. This maple bark- louse is an in- 

 sect belonging to a family of peculiar habits and histories. Un- 

 der each of the scales there was a month ago from 700 to 1,000 

 small white eggs. These eggs have since hatched into young 

 lice, which are now scattering over the trees, and will soon fix 

 themselves upon the leaves, where they will remain throughout 

 the season. They insert a tiny beak into the leaf, and suck the 

 sap. In autumn before the foliage drops they desert the leaves, 

 and fasten themselves to the twigs. Much of the sap that is 

 sucked from the foliage passes through the bodies, and falls to 

 the ground. This is frequently called honey-dew. Some of the 

 most intelhgent citizens of Columbus report that dui-ing the out- 

 break of 1884 they cleared their shade-lrees of the scales and 

 young lice by using a stream of water from the hose, forcing it 

 into the trees, and washing them off. When this simple water 

 treatment is not practicable, the next method would be spraying 

 with what is known as kerosene emulsion. These bark-lice have 

 various natural enemies, which prey upon them. These ene- 

 mies checked the outbreak quite suddenly in 1885, and probably 

 in a year or two they will reduce their present numbers below the 

 danger line; but in the mean while artificial remedies should be 

 used as much as practicable. 



— Das Wetter for May contains an article by Dr. P. Perlewitz 

 upon the influence of the town of Berlin upon its climate. He 

 finds, as given in Nature, that the difference of the mean tem- 

 perature between the town and the open country outside differs, 

 in various months, from 0.7" to 2 3°, the town being always 

 warmer. The smallest differences are in spring and winter. The 

 greatest daily differences are found to be in the evening, owing 

 to a retardation of radiation in the town. From this time the dif- 

 ference decreases until about mid-day, when there is no percep- 

 tible difference between the two localities. Dr. Hann has found 

 similar results for Vienna; but the differences there are smaller, 

 owing to the better exposure of the town station. The humidity 

 is less in the town than in the country. In the evening, in June 

 and July, the difference amounts to above 19 per cent. No 

 appreciable effect appears to be exerted by the town upon the 

 rainfall, as compared with that of the country stations. 



— Mr. Belelubsky, professor at the Institute of Roads and 

 Waterways at St. Petersburg, was some time ago instructed by 

 the minister of public works to make an examination of the sus- 

 pension bridge over the Dnieper at Kiew, which was erected some 

 forty years ago by the late Mr. Charles B. Vignoles, and to give 

 an opinion as to the quality of the metal used in its construction. 

 Luckily, from a scientific point of view, a number of extra links 

 which had been provided at the time of the erection of the bridge, 

 were still in store, and it was thus possible to determine by com- 

 parative tests what changes the material of the links of the bridge 

 had undergone in their forty years of service. The links in ques- 

 tion, according to Engineering of June 20, were about 11 feet 9 

 inches long, by llf inches broad, by 1 inch thick. Stated briefly, 

 the results of the tests show that the iron has not at all deterio- 

 rated during its long service. The mean of four specimens of 

 links taken from the bridge gave an ultimate strength of 30.7 

 tons per square inch, with an elongation of 14.5 per cent on 8 

 inches, while an equal number of tests of specimens from unused 

 links gave a breaking stress of 23.2 tons per square inch, with an 

 elongation of 13.4 per cent in 8 inches. 



— There is a disease in Japan known as kaJcke, a disorder of the 

 kidneys communicated by bacilli, and closely related to the more 

 Tirulent beri-beri. From the distribution of kakke, M. Gueit, as 



related in Nature, has drawn conclusions as to the ethnic compo- 

 silion of the present population of Japan. The fact that Chinese 

 always escape the disease, even in localities where it is very prev- 

 alent, indicates (in his opinion) that the Chinese or Mongolian 

 element is not the dominant one Ee finds three constituents in 

 the population: (1) descendants of Ainos; (2) descendants of Ne- 

 gritos; and (3) a Malayan element, which is the most prominent. 

 Wherever the Malayan goes, he brings with him the beriberi 

 order of disease, his liability to this being probably due to the 

 Hindoo blood in him. From India we find beri-beri spread, like 

 the Malays, to Madagascar on the one side, and to Japan on the 

 other; we meet with it also in Java, Sumatra, etc. According to 

 the proportion of Malay blood in the natives of Japan is the fre- 

 quency of the malady, which occurs in various forms and under 

 different names. As to the Negrito element in Japan, M. Gueit 

 found an interesting proof of it in the island of Sikok, in the form 

 of a small statuette of Buddha, having the characteristic nose 

 and hair of the Negritos. 



— The long imprisonment of beetles within furniture is treated 

 of in the last report issued by the New York State Museum of 

 Natural History. It is suggested that when such cases occur, the 

 conditions may bring about a lethargic state in which respiration 

 and accompanying phenomena are almost or entirely suspended 

 through the complete exclusion of air by the rubbing, oiling, and 

 varnishing or other polishing the furniture has undergone. This 

 instance of the imprisonment of a beetle is cited, says The Illus- 

 trated American: "In 1786 a son of Gen. Israel Putnam, residing 

 at Williamstown, Mass , had a table made from one of his apple- 

 trees. Many years afterwards the gnawing of an insect was 

 heard in the leaves of this table, which noise continued for a year 

 or two, when a large, long- horned beetle made its exit therefrom. 

 Subsequently the same noise was heard again, and a second in- 

 sect, and afterward a third, all of the same kind, issued from this 

 table-leaf; the first one coming out twenty, and the last one 

 tvventy-eight, years after the tree was cut down.'' 



— Dr. G. Hellmann, to whom meteorologists are indebted for 

 various interesting investigations into the history of meteorology, 

 has contributed to Himmel und Erde (Heft. 3 and 4, 1890) two 

 instructive articles on "The Beginnings of Meteorological Obser- 

 vations and Instruments." He divides the history of the develop- 

 ment of observations into three periods: (1) that ending with the 

 middle of the fifteenth century, up to which time they were of a. 

 very fragmentary and almost aimless character; (2) that in which 

 observations were taken at least once a day; and (3) that in which 

 they were systematically taken with instruments, dating from 

 about the middle of the seventeenth century. It is not exactly 

 known who first kept a regular meteorological journal; but Hum- 

 boldt attributes it to Columbus, on his first voyage to America in 

 1492, while the Italians also appear to have made daily observa- 

 tions from the middle of the fifteenth century. The wind-vane is- 

 by far the oldest of the meteorological instruments. In the- 

 periods of Homer and Hesiod, in the ninth and eighth centuries- 

 B.C., the qualities of the winds were correctly described. The 

 first arrangement for observing the wind-direction is the Temple 

 of Winds at Athens, which was built about 100 years B.C. A 

 picture of this tower is given by Dr. Hellmann. Eginhard, in 

 the reign of Charlemagne, denoted the winds by the four cardinal 

 points, and their variations. The first instrument for denoting 

 the force of the wind is ascribed to Robert Hooke (1667). This 

 instrument is essentially the same as that now used, and known 

 as Wild's pendulum anemometer. The absorption or organic- 

 hygrometer was invented about the middle of the fifteenth cen- 

 tury, by N. de Cusa, although the invention is generally ascribed 

 to L. da Vinci. The first condensation hygrometer is attributed 

 to the Grand Duke Ferdinand H. of Tuscany. The first con- 

 tinuous hygrometrical observations appear to have been by R. 

 Boyle, at Oxford, in June, 1666. The first thermometer is attrib- 

 uted to G. Galilei, towards the end of the sixteenth century. 

 Some few years later, the instrument was improved, although 

 the freezing-point was the only fixed point determined; and the 

 graduation was made by means of little knobs in the glass, every 

 tenth one being enamelled. The first rain-gauge was used by B. 



