62 INSTRUCTIONS TO MARINE METEOROLOGICAL OBSERVERS 



jShip''s speed (Vg). — This part of tlie message calls for the average 

 speed of the ship during the 3-hour period preceding the observa- 

 tion. The table below gives the radio code numbers corresponding 

 to various speeds. 



Symbol Vs — 8hij)'s speed 



MISCELLANEOUS PHENOMENA 



The occurrence of such ]:)henomena as lialos, coronas, waterspouts, 

 mirages, and meteors should be recorded on separate sheets if there 

 is insufficient space on the forms. 



Ohservation of meteors. — Owing to tlie exceptional opportunities 

 afforded for the purpose at sea, it would be of great scientific value 

 if the officers of ships would record the paths of brilliant and excep- 

 lional meteors and fireballs seen by them. The data needed include 

 the approximate position of the ship at the time the object appeared 

 and the civil Greenwich mean time of its ap|)earance, certainly to 

 the nearest five minutes. If any other time than Greenwich mean 

 time is used, it should be so specified. For the object itself the angu- 

 lar coordinates of its points of appearance and disappearance aj-e 

 desired. These are preferably expressed in right ascension and 

 declination, which can readily be read off from a star map if tlie 

 path is plotted thereon, or by the altitudes and azimuths if more 

 convenient. Notes giving the brightness, color, character of train, 

 and particidarly the estimated number of seconds tlie object was 

 visible are desired. If an explosion is either seen or heard, it should 

 be recorded, especially the time interval between these features if 

 both are observed. 



Records of brilliant objects, regularly made, would in a short time 

 furnish data for the calculation of many real heights and orbits for 

 such bodies — data which possess definite meteorological as well as 

 astronomical value, since they aid in the determination of the height 

 of the atmosphere. 



In addition to the foregoing, which it is desirable that all should be 

 willing to cooperate in securing, it is hoped that a few persons, 

 especially interested in astronomy, will wish to make regular observa- 

 tions at certain periods of the year when meteors are most abundant.^ 

 These are : 



3 To anyone who cares to make observations of some of these showers, regular charts, uianks, and full 

 instructions for making the observations will be furnished on application to Chas. P. Olivier, Director 

 Flower Observatory of University of Pennsylvania, Upper Darby, Pa., who has charge of this work for the 

 American Meteor Society. Other observations should be entered in the Weather Report. 



