December 28, ISSi.] 



SCIENCE. 



815 



meridian, and upon the nnilieation of time by 

 the adoption of a universal time, has agreed 

 upon the following resolutions : — 



1°. The unification of longitude and of time 

 is desirable as much in the interest of the sci- 

 ences as in that of navigation, of commerce, 

 and of international communications. The 

 scientific and practical utility of this reform 

 far outweigiis the sacrifice of labor and the 

 difficulties of re-arrangement which it would 

 entail. It should, then, be recommended to the 

 governments of all the interested states to be 

 organized and confirmed by an international 

 convention, to the end tiiat hereafter one and 

 the same system of longitudes should be em- 

 ployed in all institutes and geodetic bureaus, for 

 general geograjjhic and hydrographic charts, 

 as well as in astronomical and nautical alma- 

 nacs, with the exception of those made to pre- 

 serve a local meridian ; as, for instance, the 

 almanacs for transits, or those which are needed 

 to indicate the local time, such as the estab- 

 lishment of the port, etc. 



2°. Notwithstanding the great advantages 

 which the general introduction of the decimal 

 division of a quarter of the circle in the ex- 

 pressions of the geographical and geodetic 

 co-ordinates and in the corresponding time- 

 expressions is destined to realize for the 

 sciences and their applications, it is proper, 

 through considerations eminently practical, to 

 pass it by in considering the great measure of 

 unification proposed in the first resolution. 



However, with a view to give satisfaction at 

 the same time to very serious scientific con- 

 siderations, the conference recommends, on this 

 occasion, the extension, by tlie multi|)lication 

 and perfection of the necessary tables, of the 

 ai)plication of the decimal division of the 

 quadrant; at least, for the great operations of 

 numerical calculations for which it presents in- 

 contestable advantages, even if it is wished to 

 preserve the old sexagesimal division for the 

 observations, for charts, navigation, etc. 



3°. The conference proposes to governments 

 to select for the initial meridian that of Green- 

 wich, defined by a point midway between the 

 two pillars of the meridian instrument of the 

 observatory of Greenwich ; for the reason that 

 that meridian fulfils, as a point of departure 

 for longitudes, all tlic conditions wisiied for 

 by science, and because, being at present the 

 best known of all, it oflfers the most chances of 

 being generally accei)ted. 



4°. It is suitable to count the longitudes, 

 starting from the meridian of Greenwich, in 

 the sole direction from west to east. 



5°. The conference recognizes for certain 



scientific wants, and for the internal service in 

 the great administrations of routes of com- 

 nninication, — such as tlie railways, steamship- 

 lines, telegraphic and post routes, — tiie utility 

 of adopting a universal time, along with local 

 or national time, whicii will continue necessa- 

 rily to be enii)loyed in civil life. 



C°. The conference reconunends as the point 

 of departure of universal time and of cosmo- 

 politan dates the mean noon of (ireenwich, 

 which coincides with the instant of midnigiit 

 or with the commencement of the civil d.\v, 

 under the meridian situated twelve hours, or 

 a hundred and eighty degrees, from (ireen- 

 wich. 



It is agreed to count the universal time from 

 hour to 24 hours. 



7°. It is desirable that the states which, with 

 a view to adhere to the unification of longi- 

 tudes and of time, find it necessary to change 

 their meridians, should introduce the new sys- 

 tem of longitudes and of hours as soon as 

 possible. 



It is equally advisable that the new system 

 should be introduced without delay in teach- 

 ing. 



8°. The conference hopes, that, if the entire 

 world agrees upon the unification of longitudes 

 and of hours by accepting the meridian of 

 Greenwich .is the point of departure. Great 

 Britain would find in this fact an additional 

 motive to make, on its part, a new step in 

 favor of the unification of weights and meas- 

 ures bv adhering to the Convention du mitre 

 of the'-20th of M.ay, 1875. 



9°. These resolutions will be brought to the 

 knowledge of the governments, and recom- 

 mended to their favorable consideration, with 

 an expression of a hope that an international 

 convention — such as the government of the 

 United States has proposed — for confirming 

 the unification of longitudes and of time should 

 be decided upon as soon as possible. 



ORIGIN OF THE MESODERM. 



The origin and composition of the mesoderm 

 has been the subject of perhaps moie discus- 

 sion than any other single point in the whole 

 range of emiiryology. Observers have given 

 the most conflicting statements, for the most 

 part due to incomplete observations ; but now 

 we are at last in a position to eliminate many 

 of the false descriptions and to harmonize 

 fairly well those we must regard as correct. 



The first important advance was accom- 

 plished by His, who made the fundamental dis- 

 covery that the mesoderm is not homogeneous, 



