apparatus a common thermometer may be used, the bulb of 

 uhich is surrounded by floculent black wool. 



7. Note every apjiearance of shootiug stars and fire balls; 

 give their direction of motion among the stars, starting and ending 

 jDoints; give the intensity of light of fire ball as compared 

 with that of day ; the size compared with that of the moon. If 

 an explosion is observed listen for sound for perhaps tAVO or 

 three minutes. Make special observations for shooting stars on 

 several nights about the 12th or 13th of November. Observa- 

 tions should be kept up for several nights on, before and after 

 these epochs for the jDurjoose of comparison. Other periods 

 less marked may be noted, namely: April, from 23d to 24th; 

 June, from loth to 20th; October 18th; December 6th and 7th; 

 January 2d. 



8. The temperature of the surface of the water should be fre- 

 quently taken, first to ascertain if there are any variations from 

 day to day, when the* vessel is at rest in the same place, and, 

 second, to determine the variations from place to place when 

 the vessel is in motion ; in certain cases, such as entering a warm 

 stream the change may be very sudden. 



For determining the surface temperature, the Avater may be 

 drawn in a bucket, care being taken to let it remain long enough 

 overboard to obtain the temperature of the water. If a ther- 

 mometer be let down into the water to obtain the surface, or 

 deep sea temperature, its bulb should be surrounded with seve- 

 ral coatings of cloth, in order that the tempterature may remain 

 long enough stationary to admit of its being read on deck with- 

 out sensible change. Care, however, must be taken that the 

 thermometer remain in the water sufficiently long to acquire the 

 temperature of the latter. 



9. Frecjuent observations should be made to ascertain the direc- 

 tion of currents by a comparison of dead reckoning with astro- 

 nomical observations, and, to aflbrd data for subsequent deter- 

 minations, bottles containing a sheet of paper, giving the lati- 

 tude, longitude, and time, with directions as to where the paper 

 is to be sent by the finder, should be frequently thrown over- 

 board. The bottles should be of transparent glass in order that 

 the white paper may be seen at a distance. The ordinary black 

 bottle is so near the color of the sea as to escape notice unless 

 cast on the shore by a wave. 



