[85] OPERATIONS OF SCHOONER GRAMPUS. 575 



SUGGESTIONS FOR COLLECTING AND PRESERVING SPECIMENS AND FOR OBSER- 

 VATIONS. 



Note air temperatures and the state of the weather at regular periods. 

 This is probably your custom at all times. 



Take temperatures at the surface regularly, aud read the thermom- 

 eter with great care. Be certain that it has been immersed a sufficient 

 length of time to take the true temperature. Indicate by latitude and 

 longitude, or by a mark on the chart, the exact position where each 

 temperature observation was made. Take the temperature of the air 

 at the same time that you take the temperature of the water. 



Preserve all the materials obtained in each towing in a bottle by 

 itself, and label these bottles carefully. Each label should have writ- 

 ten on it the date, the time of day, the latitude and longitude, and the 

 length of time the towing net has been out, or the distance it has gone 

 through the water. Make as many towiugs as possible. 



Each time that a lot of mackerel is taken, cut out and preserve the 

 stomachs of several of the fish in a bottle, first cutting the stomachs 

 open so that the alcohol will enter freely. Put labels on these bottles 

 stating the latitude and longitude where the fish were taken, the date, 

 and time of day. 



Note the occurrence of every school of mackerel, and of all stray 

 individuals, and their abundance. Note any observations you can make 

 in regard to their movements ; in what direction they are going; do 

 they leave the surface and sink for any reason ; what is the cause of 

 this? 



Note whether the fish contain spawn. Preserve specimens of the fish 

 from time to time in alcohol, first make a very large cut in the ventral 

 side so that the alcohol may freely enter the visceral cavity. Label all 

 such specimens. 



Where you find schools of mackerel is there always an abundance of 

 the small surface feed ? Make towiugs at such times. 



Do you ever find the schools of mackerel chased by other fish, and 

 by what kinds ? 



Make notes on the other fishes which you observe. 



The following morning received telegraphic orders to wait at Hamp- 

 ton Roads until further instructions arrived, which would be sent by 

 mail. «We remained in the harbor from the 26th to the 30th of April, 

 during which time all the necessary stores were taken on board, in- 

 cluding a lot of jars, in which to preserve specimens, that were received 

 from Washington. 



