CHAP. VI.] DEEP-SEl DREDOING. 263 



venient. Their great disadvantage is that if the 

 bottles on which they are fixed get wet they are apt 

 to come off. 



Pencils are sold by seed-merchants for writing on 

 tallies which are to be exposed to rain. Perhaps 

 the safest plan is to mark the number and date with 

 such a pencil on a shred of parchment or parch- 

 ment paper, and put it into the bottle. This may 

 seem a trifling detail, but so great inconvenience 

 constantly arises from carelessness in this matter, 

 that I feel sure of the sympathy of all who are 

 interested in the scientific aspect of dredging when 

 I insist upon the value of accurate labelling. 



It is of even greater importance that certain 

 circumstances relating to every individual haul of 

 the dredge should be systematically noted, either 

 in the dredger's diary, or on a special form prepared 

 for the purpose. The precise position of the station 

 ought to be defined in shore dredging by giving 

 the distance from shore and the bearino's of some 

 iixed objects; in ocean dredging by noting accurately 

 the latitude and longitude. In the ' Lightning,' in 

 1868, we dredged at a station about 100 miles to 

 the north of the Butt of the Lews, and came upon 

 a singular assemblage of interesting animal forms. 

 Next year, in the ' Porcupine,' we were anxious to 

 try again the same spot to procure some additional 

 specimens of a sponge which we were studying. 

 The position had been accurately given in the log 

 of the ' Lightning,' and the first haul at a depth of 

 upwards of half a mile gave us the very same group 

 of forms which we had taken the year before. On 

 our return Captain Calver again dropped the dredge 



