Peck n. Harrington, Plankton fles Puget-Soimd. 



Fig. 1. 



Over one such depression of the bottom, at Lat. 48 5' N., Long. 

 122 38' W. samples of water were taken for quantitative estimate of 

 the plankton through a vertical of 112 fathoms. The date was Sep- 

 tember 1, 189f>, at 2 o' clock in the afternoon, at low water slack 

 tide, with the sky overcast, breeze slight, and practically no sea. 

 The distance of 112 fathoms was divided into four equal parts, so 

 that three intermediate samples were taken at regular intervals be- 

 tween the surface and bottom collections. 



The apparatus used in obtaining the samples of water from the 

 several depths was constructed from an earthenware jug containing 

 two litres, closed with a hard rubber cork of the largest size that 

 could be urged into the opening. This cork is bored and fitted with 

 a piece of glass tubing bent just above the cork and hermetically 

 sealed at the outer end. A thermometer should also have been placed 

 in the jar through a second perforation of the cork but we lacked 

 this important accessory. The jar is then heavily weighted with bars 

 of pig-iron, and swung w r ith fine steel wire suitably measured oft' into 



fathoms, and a light guide line also 

 attached to the bent glass tube. Such 

 a device is represented in the accom- 

 panying cut, Fig. 1, showing the jar 

 in readiness for lowering. W is the 

 steel wire by which the stone jar is 

 suspended, GL being the guide line 

 attached to the bent glass tube. The 

 iron weights are so attached as to 

 keep the jar in its perpendicular po- 

 sition. The apparatus may then be 

 rapidly lowered to any given depth 

 from the deck of the boat by means 

 of a windlass, while the guide line 

 is simultaneously paid out in excess. 

 In our collections the water being- 

 smooth the guide line was issued 

 from a kiff drifting a few yards 

 away. As the required depth is 

 reached the guide line is carefully 

 hauled taut and then given a sharp 

 pull which breaks the bent glass 

 tube at the angle and so allows the 



water to rush rapidly in, because of the surrounding pressure, and 

 fill the jug which is then drawn to the surface. We believe that there 

 is practically no intermixture of water from other levels as the jar 

 ascends, even in the short glass tube that remains in the cork; there 



GI. 



