30 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



method appears to consist especially in the convenient form 

 into which he throws the work of solving that portion of the 

 computation called the solution of Lambert's equations; and 

 the method, as elaborated by him, appears to be well worthy 

 of the consideration of those engaged in such calculations. 

 Vostokoff, Warsaw, 1873. 



THE OBSERVATION OF AURORAS. 



It has been suggested by Ileis, the editor of the Wochen- 

 schrlft, that it is highly advisable for meteorological observ- 

 ers throughout the world to arrive at a more precise and 

 systematic method of observing the Northern Lights. He 

 remarks that it is most desirable to have accurate drawings 

 of the appearance of the aurora, together, of course, with es- 

 timates or measures of all its dimensions, made at the begin- 

 ning of each hour, and, if possible, at the beginning also of 

 each quarter-hour, and that the European observers might 

 uniformly adopt Berlin mean time, in order that the several 

 drawings and estimates may all refer to the same moment. 

 Such simultaneous observations have a very great advantage 

 over those taken according to local time, and offer no difficul- 

 ty whatever, inasmuch as every observer, knowing his longi- 

 tude, and having his clock well regulated, may easily select 

 the exact minute corresponding to the quarter -hours at 

 Berlin. 



It is evident that this same suggestion carried out for 

 America will add immensely to the value of the almost in- 

 numerable records that are now being received, not only by 

 the government officials at Washington, but by the societies 

 scattered throughout the country. In order to further this 

 system of synchronous observation, which ought to extend 

 throughout the whole world, since many auroras are simul- 

 taneously visible in both hemispheres, we note that the longi- 

 tude of Washington from Berlin is six hours one minute and 

 forty-eight seconds ; and with this as a starting-point, it be- 

 comes possible for American observers to time their observa- 

 tions by Berlin time. While these remarks apply especially 

 to the auroras that continue for several hours, and extend 

 over a large section of the heavens, they are not the less ap- 

 plicable to those small auroral displays, and especially to the 

 narrow auroral arches, that so frequently span the heavens 



