nf practical C 



7C9 



and these two plates are joined at their 

 lower extremities, by means of two cross- 

 I bars, C C and D D, so as to form an angle of 

 about 45 with the plane of this position ; 

 each bar is 5 inches in length, by three-and- 

 a-half-eighths in diameter. The arms E F 

 and E F are each 16 inches in length, by 

 3i inches in diameter, and play upon the 



BALL'S DREDQB. 



cross bars by means of double swivel joints, 

 as seen at E E and E E. Their anterior ex- 

 tremities at F are beaten flat, so as to meet 

 closely, and vertically, and are pierced for 

 the reception of the bolt II, which at the 

 same time passes through the extremities of 

 what may be termed the birdie ring G, to 

 which the rope is affixed. The head of bolt 

 H is pierced to receive the end of a little 

 iron spike, for the better working of the 

 screw ; and at any time, by drawing the said 

 bolt H and folding the arms inwards, the 

 whole apparatus may be stowed away in a 

 moderate-sized carpet bag ; for its weight 

 will not exceed 7 or 8 Ibs., and the cost is 

 only 7*. In no case should the bag exceed 

 18 inches in depth ; one may be made of best 

 twine, with meshes half an inch apart, and 

 another of cheese cloth, or serge, for fine 

 work. A raw hide, such as has been im- 

 ported as a wrapper for bales of tobacco, or 

 tallow, and which may be purchased in 

 London for Is. 6d., will make three bags of 

 a most durable and efficient description, and 

 they should have holes a quarter of an inch 

 in diameter, cut with a punch, or simply 

 stabbed with a knife, to facilitate the dis- 

 charge of the water ; and to save the trouble 

 of canting the bag after it is drawn up from 

 the water, there should be a slit five inches 

 in length cut in the bottom, and laced with 

 a thong. The strength of the rope required 

 for Ball's Dredge must be regulated entirely 

 by the depth at which it is employed ; in 



all cases a 14 Ib. weight should be attached 



six inch 

 dredge. 



to the rope 



es distant from the 



Two or three moderate-sized sieves are 

 required for sifting mud and sand; the height 

 of the sieves may be 4 or 5 inches, and the 

 meshes of their copper or brass wire bottoms 

 should be one-tenth of an inch apart ; by 

 attaching three strings which are held in the 

 hand, the more valuable contents of the sieve 



are readily exposed by repeated dippings in, 

 the water. 



COLLECTING Our land shells may be 

 taken in the greatest abundance during moist 

 weather, or at morning or evening, creeping 

 about pathways and old walls, in gardens, 

 fields, woods, and heaths. Many species are 

 taken by a careful search below stones and 

 the bark of trees, amongst moss, and on va- 

 rious plants, by means of the sweeping-net ; 

 whilst the tin spoon and water-net readily 

 procure those which frequent streams and 

 ponds : but lakes must be searched either 

 with the Gangui or with the Dredge. 



For the marine species, the sea-shore 

 should always be searched after a storm ; 

 shell sand, and the roots of tangle and 

 other marine plants, yield many peculiar 

 species, and so do the rocks laid dry at the 

 recess of every tide, and on some parts of the 

 coast the curious Pholades which burrow 

 into rocks are pretty common, whilst the 

 sandy shores also yield their peculiar spe- 

 cies. A dimple in the sand points out the 

 situation of the Solen or Spout-shell, and 

 two little apertures that of the Tellinae. 

 Many fine species may be procured from the 

 stomachs of fish brought to market, from the 

 nets, lines, and traps of fishermen ; but the 

 dredge is the grand implement, which should 

 be in the hands of every sea-coast naturalist. ! 

 Having arrived at the fishing ground, ascer- ] 

 tain the depth of the water, and the nature 

 of the bottom, with a sounding lead ; register 

 these data, which are of the greatest im- 

 portance, in a pocket journal ; drop the 

 dredge overboard, allowing one third more 

 line than the ascertained depth, and drag 

 the dredge along by sailing or rowing ; when 

 full let it be dragged into the boat. Let the 

 Nudibranchiate Mollusca, Holothurise, and 

 other soft animals, demand your first atten- 

 tion ; make a sketch of all rare and curious 

 forms, and wrap each specimen in a piece 

 of tinfoil, before putting it into a bottle of 

 alcohol, or Goadby's solution, or into a bottle 

 of sea-water, if you desire to study their 

 habits to advantage. The remainder of the 

 contents are thrown into a tub, and the 

 dredge lowered whilst they are being sorted. 



PRESERVING The animals in shells must 

 be killed by immersion in hot water : as 

 univalve shells are apt to crack under such 

 treatment, the heat must be gradually in- 

 creased by adding more hot water : when | 

 the animal of a bivalve is dead, the valves of 

 the shell separate a little. The animal when 

 dead is removed with the point of a knife, 

 or crooked pin. The operculum where it 

 exists is wrapt in paper and put in the mouth 

 of the shell, which is then laid on a towel to 

 dry in the sun, and a thread is wrapt round 

 the bivalves to keep them closed till dry ; 

 but previous to this, all marine shells should 

 have a bath in fresh water, for several hours, 

 to extract the saline particles, which would 

 otherwise greatly injure the specimens. All 

 extraneous bodies, such as sea- weed, Serpulaa 

 and Acorn shells, must be removed with the 

 point of the knife, or with a hard brush and 

 water : all shells, but especially such as have 

 been picked up along shore, have their ap- 



