November 6, 1891.] 



SCIENCE. 



257 



the surplus water escapes), and so on. Thus, in the evening of 

 July 6, 1890 after a stiff west-north-west squall, there were eight 

 pronounced oscillations, the strongest showing about 1.4 inches 

 difference of level in sixteen minutes. In another case, the har- 

 bor level rose higher (ban it had done for fifteen years. The latter 

 squall (a strong south-west one) affected also the Trieste mareo- 

 graph, which showed nine wide oscillations with a mean period 

 of one hour forty-six minutes. Lieut. Gratzl suggests observa- 

 tions as to whether sudden impulses of " bora " against the Italian 

 coast might not heap up the water there, so that a return wave 

 might affect the Austrian mareographs; also whether certain sud- 

 den currents which injure fishermen's nets in the Dalmatian canals 

 may not be connected with those waves. 



— Last winter there were some reports, says Nature, that sun- 

 set phenomena had greatly increased in brilliancy, as if something 

 similar to the optical disturbance following the Krakatoa erup- 

 tion had occurred. Herr Busch has remarked (Met. Zeit.) how 

 difficult it is to recognize gradual variations in such phenomena, 

 or to say where they pass beyond the normal. Even the brown- 

 red Bishop's ring may be regarded as quite normal in winter. A 

 much more sure method of finding an optical disturbance of the 

 atmosphere is measurement of the polarization of light. Herr 

 Busch has carried this on systematically for some years with a 

 Savart polariscope, and a simple instrument for measuring angles, 

 determining the height of the two neutral points (Babinet's and 

 Arago's) at sunset. Now, the values for this height, in February 

 and May last, considerably exceed those obtained in the three 

 previous years, and come near those in 1886, when the last traces 

 of the great atmospheric disturbance were still everywhere per- 

 ceptible. It would seem, then, that some optical disturbance has 

 been-ieally present, the beginning, extent, and cause of which, 

 however, are in obscurity. The desirability of systematic observa- 

 tions in different places is pointed out. 



— For the prevention of sea sickness, a curious notion seems to 

 be common that the stomach should be kept as full as possible. 

 Thus have we seen stout old men and women take with praise- 

 worthy persistence — had tlie result beeu satisfactory — biscuits, 

 brandy and soda, apples, a pint of porter, a red herring, and 

 various other edibles and potables, says the Lancet, with an entire 

 want of success in retaining them, a course of procedure peculiarly 

 trying to those who happen to be standing, or rather lying, on the 

 verge of the act of vomiting. Were we to counsel those who are liable 

 to this affection, we should recommend as follows. Take a moderate 

 meal two hours befox'e going on board. Remain on deck amid- 

 ships, well protected against cold, as long as possible. As soon as 

 the premonitory symptoiis appear, retire to the berth, undress as 

 quickly as possible, and lie flat on the back for the Hrst tweUe or 

 even twenty-four hours without food. Then take a small portion 

 of dry bread and roast beef without fluid ; this the stomach will 

 probably retain. If there is much movement of the vessel, lie 

 quiet again, or even go upon deck, and in the course of thirty-six 

 or forty-eight hours the system will have recovered itself, and no 

 further trouble will be experienced. It is a mistake to introduce 

 a quantity of fluid, even of strong coffee, into the flaccid stomach, 

 but if sickness ]iersist, a glass of champagne will probably prove 

 serviceable. In some few persons quinine or antip^rin, chloral 

 or potassium bromide, may act well, but as a nzle medicine of all 

 kinds should be eschewed by those who do not wish to aggravate 

 what is already hard to bear. 



— Caoutchouc, or india-rubber, is produced in Dutch Guiana 

 under different species, the must important of which is " balata" 

 or ''milk o' the bullet tree, 'the export of which, says Consul 

 Wyndham of Paramaribo, is attaining considerable proportions, 

 and will, it is believed, be very productive for a time only, as 

 there is no forest conservancy law in the colony. Persons who 

 are granted tracts of land for the gathering of this product are 

 Tincontrolled in their method of drawing the milk, which results 

 in trees being totally destro\ed to get the greatest amount of milk 

 by the quickest and most inexpensive method. The district 

 where the largest quantity of balata trees are known to exist in 

 the colony is that bordering on tbe Correntyne River, known in 

 Dutch Guiana as the " Nickerie district." Balata is treated by 



the manufacturers simply as a superior kind of gutta-percha, and 

 therefore its name disappears when manufactured ; nevertheless 

 balata is distinctly different from gutta-percha, and this is mani- 

 ested in some of its physical characters ; for instance, it is some- 

 what softer at ordinary temperatures and not so rigid in the cold. 

 Besides the bullet tree, there are trees or plants known as the 

 Tonckpong, which, give a valuable rubber, and again Bartaballi and 

 Bushrope. to which collectors do not appear to have given a 

 name. The india-rubber balata industry, although carried on in 

 Dutch Guiana in a desultory way for a long time, has never until 

 quite recently assumed sufficient importance to cause the local 

 government to legislate upon it. As yet the law only lays down 

 the regulations under which concessions are granted, and does not 

 deal with the supervision or treatment of the trees, or the method 

 of extracting the milk. Caoutchouc is yielded both by trees and 

 vines. Those already mentioned are, as far as it is known, the 

 principal ones in the colony, and the method of collecting the 

 milk is by cutting down trees, by incisions, and by circling the 

 tree. In each case there is no protective law, and the trees are 

 generally ruined. The chief port of export is Demerara, and as 

 yet no export duty exists, but as the production increases it is 

 expected that it will not escape taxation. Nothing has been done 

 to cultivate the plant, neither does the soil seem to favor its 

 growth except in some peculiar circumstances. 



— The comet found by Professor Barnard of the Lick Observa- 

 tory on Sept. 37 proves to be the long-looked-for Tempel-Swift 

 comet. It was first discovered by Tempel in 1867, and by Swift in 

 1880. It was not until the latter date that it was settled that a 

 new short-period comet had been added to the list. Mr. Bossart, 

 one of the compiitors connected with the Paris Observatory, had 

 computed the perturbations from 1880 to date, and had also pre- 

 pared an ephemeris. The date of perihelion as determined by Mr. 

 Bossart appears about 3.4 days late. With that correction, the 

 following ephemeris has been computed. The epoch is for Berlin, 

 midnight. 



1891. R. A. Dec. 



h. m. s. deg. min. 



Oct. 30 31 21 13 -I- 6 19 8 



Nov. 1 26 3 7 3.4 



" 3 31 17 7 48.9 



The f jlliwing are the positions for Wolf's comet for the next ten 



days. The epoch is for Greenwich, midnight. 



1891. R. A. Dec. 



b. m. s. — deg. min. 



Nov. 8 4 ?8 30 5 .59.4 



'■9 38 1 6 38.1 



" 10 37 33 6 53.3 



" 11 37 7 17.7 



" 13 . 36 3S 7 43.7 



" 13 35 55 8 6.9 



" 14 35 30 8 30.5 



" 15 34 45 8 53.4 



"16 34 8 9 15.7 



" 17 33 31 9 37.3 



" 18 4 32 53 9 58.1 



The comet discovered by Professor Barnard on Oct. 3 is passing 



very rapidly southward, and can only be seen in the southern 



hemisphere. An ephemeris for following dates is not at hand. 



— Dr. Kirkwood, professor of astronomy in the University of 

 Indiana, has been appointed to lecture on astronomy at Stanford 

 University, California. 



— The regents of the University of California have elected Dr. 

 Henry Crew, instructor in physios at Haverford College, as an 

 astronomer at the Lick Observatory. 



— It is hinted in the October number of the Observatory that 

 Dr. Huid, who has been for many years the superintendent of the 

 English Nautical Almanac, will soon retire from that position. 



— Professor Asaph Hall, the eminent astronomer, who has been 

 for many years in charge of tbe large telescope at the United 

 States Naval Observatory, has been placed on the retired list of 

 the navy. 



