ii6 



NATURE 



[June 4, 1891 



Mean density of the earth — 



5-576 ±0016. 

 Surface density of the earth — 



256 ±0'i6. 

 Length of the seconds pendulum (<^ = latitude) — 

 39*012540 + o "208268 sin-^) inches. 

 Acceleration due to gravity — 



32086528 + 0-171293 sin> feet. 

 Length of the sidereal year— 



36sd. 6h. 9m. 9-3143. 

 Length of the tropical year at time t — 



3656. 5h. 48m. 46-0695. - 0-53675S. r ~ ' ^° \ 

 Length of the sidereal month — 



27d. 7h. 43m. 11-5243. - 0-0226715. / ~ ^ ° Q\ 

 Length of the synodical month — 



29d. I2h. 44m. 2-8415. — 0-0265225. ( ~ ^°°° Y 

 Length of the sidereal day-— 



86164-09965 mean solar seconds. 

 Ratio of the mean motions of the sun and moon — 

 0-07480 I 329 I 12. 



Mass of Mercury (Sun = i), ^ \ — ■ 



"8374672^1765762 



I 



408968 ± 1874 



I 



327214 ± 624 



I 



309350D ± 3295 



I 

 1047-55 ± 0-20 



I 



3501 -6 ±0-78 



„ Venus ,, 



„ Earth 



,, Mars ,, 



,, Jupiter ,, 



,, Saturn ,, 



,, Uranus ,, — -p. — "-^- — -p 



" 22600 ± 36 



" N^Pt""^ " 18780 ±300 



„ Moon (Earth = I) g^.^egi 0-238 

 Constant of solar parallax — 



8"-8o9o5 ± o"-oo567. 

 Mean distance of earth from sun — 



92796950 ± 59715 miles. 

 Eccentricity of the earth's orbit — 



0-016771049. 

 Lunar inequality of the earth — 



6" -52294 ± o" -01 854. 

 Lunar parallax — 



3422"-542i6 ± o"-i2533. 

 Mean distance from earth to moon — 



238854-75 ± 9-916 miles. 

 Eccentricity of moon's orbit — 



0-054899720. 

 Inclination of moon's orbit — 



5° 8' 43" -3546. 

 Mean motion of the moon's node in 365^ days — 



- 19° 21' i9"-6i9i + o"-i4i36 ( ^ ~ ^^°° \ 

 Parallactic inequality of the moon — 



1 24" -95 1 26 ±0" -08 1 97. 

 Constant of luni-solar precession — 



_ ^ ^ ^ . 5o"-357io±o"-oo349. 

 Constant of nutation — 



9" -22054 ±0" -00859. 

 Constant of aberration — 



2o"-4545i ±o"-oi258. 

 NO. I 127, VOL. 44] 



The time taken by light to traverse the mean radius of the 

 earth's orbit (the light equation) — 



498-005955. ± 0-308343. 

 The velocity of light in vacuo per second of mean solar time — 

 186337-00 ± 49-722 miles. 



In order to improve the system of constants discussed, Prof. 

 Harkness thinks that the parallax of the moon should be deter- 

 mined by the diurnal method at one or more stations as near as 

 possible to the equator, and that the Observatories in the northern 

 and southern hemispheres should co-operate with each other for 

 two or three years in systematically making meridian observa- 

 tions of the moon to improve our knowledge of its parallax. 

 Numerous pendulum observations are required, and new deter- 

 minations of the constants of aberration and nutation by as many 

 different methods as possible. The most probable coefficient 

 of the lunar inequality of the earth's motion should be obtained 

 from Greenwich and Washington meridian observations of the 

 sun, whilst the opposition of Mars in 1892, and favourably situated 

 asteroids, should be utilized for new determinations of the solar 

 parallax. 



The laborious character of an investigation which leads to the 

 results here given is patent to all. To say, therefore, that all 

 the computations involved were made and checked by Prof. 

 Harkness himself is to testify to industry very rarely excelled. 



TECHNICAL EDUCATION IN RUSSIA. 



A N interesting report on technical education in Russia has 

 "^^ been laid before Parliament by the Foreign Office. It is 

 a digest by Mr. Harford of a very voluminous Report, compiled 

 by Mr. Anopoft", Director of the Nicholas Industrial School at 

 St. Petersburg, on technical education in Russia, and is de- 

 scribed by Sir R. Morier as giving an exhaustive review of all 

 that has been done during the last 20 years in Russia in this im- 

 portant branch of national education, and is of special interest as 

 furnishing information on the most recent legislation respecting 

 schools about to be founded. 



M. Anopoff confines himself to giving full details of inter- 

 mediate and elementary technical and industrial teaching 

 institutions, without attempting a description of the higher 

 schools. The establishment of these former classes of schools 

 dates, he says, from only some 25 years back, but in that short 

 space of time they have spread to the confines of the Russian 

 Empire. In 1883, a special section for technical and professional 

 education was created in the Ministry of Education. According 

 to the new regulations of the Realschtden, intermediate and 

 elementary technical and industrial schools are to be opened at 

 the public expense. M. Anopoff remarks, however, that these 

 new schools cannot be expected to be at first as successful as the 

 existing schools with their long practical experience. He adds, 

 too, that the greater number of the technical schools in Russia 

 were founded at the initiative, and often even at the expense, of 

 local societies and private persons. The various technical and 

 industrial institutions in Russia are divided into five groups : — 

 (i) Technical schools with the course of intermediate schools re- 

 sembling the Reahchulen, but differing from them by their 

 professional character being more strongly marked. The task of 

 these schools, which, as regards the knowledge required, is about 

 equivalent to the standard of the Reahchulen, with a course 

 of from six to ei^ht years, consists in imparting a general 

 acquaintance with the technical and partly commercial subjects 

 which are indispensable for the assistants of engineers, and for 

 independent managers of small technical undertakings. (2) To 

 the second group may be referred institutions in which subjects 

 of general education are taught within the scope of the courses of 

 municipal schools and district and village schools with two 

 classes. From those who enter them a knowledge is required 

 approximate to the scope of primary schools, the full course of 

 study lasting from four to six years. In these schools, besides 

 the subjects taught in the municipal schools under the regulations 

 of 1872, the following additional subjects are taken up : physics, 

 mechanics, technology of meials and woods, bookkeeping, &c., 

 while to drawing, both freehand and geometrical, much attention 

 is given. The object of these institutions is the preparation of 

 skilled artisans for factories, of lesser mechanical specialists, 

 machinists, and draughtsmen. In this category should be in- 

 cluded the railway schools, but as they are under the control of 

 the Ministry of Communications, and serve certain special ob- 



