[Vol. v., Na Itt.
��The nnlfonnlty and continuity of the system of ob> aerrations make the resultB of muirli interest. Three sentinels Are on duty during the night, and each is required to report, when relieved, whether he hu seen any auroral light during the night, and, if not, whether the aky has been enflirieiitly clear to pei^ rait any to be visible, At the end of the year the number of auroras, taking the mean result from the three observers, are added, and also the number of nights on 'which auroras could not have been seen owing to clouds. The probable number for the year is obtained by increasing the observed number i[i the same ratio as that of the cloiitiy iilgbtH to the clcnr nights. The results are shown in the following table. The last column of the table gives the aver- Hge number of suu-apots as observed by Prof. D. P. Todd.
Bumman/ rtf auroraX records for flfleen vcitrs.
�� �Ci™r.ky.
�Clondy
� � �Avsr-
� � � � � � � �YCH.
� � � � � � �Nlghu
� �Nightt.
�,
� �yeir.
�:,"«.
�1810
�3M
� �SO
� �^,
�M
� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �IW
� �T4
� �I
� �■Tfl
�im . .
�SM
�t
� � �I
�^!
�ii
� � � � � � � � �isu . .
�fil
� � � �*}
�«
� � �IBV
� �m
� �a
�■u
� ��— According to the explorer, Col. PrjeTalskl, Thibet appears to be a paradise for gold-diggers. Id tile tetter in which he describes the discovery of the sources of Uie Yellow Kiver (the Hoang-ho), he writes r In the neighborhood of the southern slope of the Burchan-Budda, we met with about thirty friendly Tauguts, who were employed in gold-wash- ing. The whole of uortheru Thii>et seems very rich in gold. At the gold-washing place we visited, the Tauguts were digging the gravel containing the gold from a depth of only from almui one to two feet; and, though the gold-washing was only done in the most primitive way, the Tauguts sliowed us whole haodfuls of gold In large pieces, of which none were tmaller than a pea. Doubtless, careful worlcing of the gold- washing process would yield enormous treas- ures. It seems to me, too, that the prophecy is not too bold, that Thibet, In time, will prove a. second California.
^ Dr. Aurel Schuize, the son of a German colonist in Natal, has recently returned frooi a successful journey into the interior. He advanced up the Eu- ando, or Chobe, for a considerable distance, and pro- ceeded thence lo the Kubango, where Ills farther progress to the west coast was stopped through the liostlle attitude of the natives. He returned tu Natal by way of lake Ngami and the Transvaal.
��— A. Ricijehaa presented a report to the Council of hygiene of the department of the Seine, In which be states that viuicline should not be used for alimen- tary purposes, as it is injurious to health. This sub- stance has been recommended tor use in pastry, as it is said to show no tendency to become rancid.
— The Acadtfmie des sciences offers for this and the three following years a medal of the value of three thousand francs, fur some important Improve- ment in the theory of the electric iransnilsslon of work. The Bordin prize of three thousand franca Is also to be given for the best memoir on the origin of atmospheric electricity, and the causes of the great development of electrical phenomenaln storm-clouds; this to be sent In before the Ist of Jime next, the other before the Ist of June. 1888.
— Tea-cultivation is malting some pn^ress in Italy. In the province of Norara a plantation is reported to be doing well; and at the agricultural show.at Mes- sina, in 1SS2, Signor d'Amico exhibited a hundred plants lliree years old, that had been grown in the province of Messina. The Italian government has sent lo Japan for a supply of plants.
— The prize offered by the SocifilS d'encourago- ment pour I'industrie nationale, of forty pounds, for the discovery of ' a new alloy useful in the arts,' has l>een an arded to P. Manhtia, on account of his discov- ery of the value of an alloy of copper and manganese tor Improving the quality of commercial copper. Manhtis prepares an alloy of seveuty-Uve per cent copper, and tweuty-Bve per cent manganeae, and adds It lu small quantities to the molten copper after refin- ing and just before casting, stirring the bath of mctil at the same time. The manganese of the alloy 1( stated to immediately combine with the oxygen of the dissolved cuprons oxide, forming a manganlferous slag which is easily removed. The operation Is cheap, and very much improves the quality of the copper »a treated. Also several of the principal alloys ot cop- per, bronze, gun-metal, brass, are of superior quallly when prepared with copper purifled in this manner; and copper so treated is more slowly acted upon by
— Obrecht published, iu a recent number of the Cumptea renitui, hia result for the solar pHrallnx as de- rived from measures of the photographs of the tran- sit of Venus of 1S74, obtaitsed by the astronomers of the French expeditions. The value found is 8.80", t)ut it is not final, having still to be corrected for some elements in the calculation whose precise value is as yet unknown, A few years ago, Professor Todd, in a similar way, obtained a preliminary result from the American photographs of the same transit, which was S.8S" for the solar parallax.
— ■The sun,' by Rev, Thomas W. Webb (New York. Indimlriiit pubticiition company. 1885), is ' n familiar description of the sun's phenomena.' It is after the style ot the iclenlific primers, and gives in seventy-seven small pages of coarse type a clear tdett of how the distance of the earth from the sun is de- termined, and of what is going on upon the sun's surface. ,
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