180 REPORT — 1881. 



established that in the clear water of tlie Mediterranean, advantageous 

 results would be obtained by the employment of diving. On returning 

 to Italy Dr. Dohrn made application to the Italian Minister of Marine 

 for the loan of a ' Scaphander ' apparatus, a request which was granted 

 with the greatest liberality. By means of these appliances Dr. Dohrn 

 and several of the gentlemen of his staff have been enabled during the 

 last two years to investigate, by actual inspection, the coast and sea-bed 

 at the following localities : — The neighbourhood surrounding the Castel 

 deir Uovo, the "sea-bed of the Chiaja and Mergellina, all the coast and 

 grottos of Posilippo, the Secca della Gajola, the whole of the circum- 

 ference of Nisita, the bay of Baja between Pozzuoli and Capo Miseno> 

 the coasts of Procida and Vivara, the Secca di Vivara, different points of 

 the coast of Ischia, also a few at Ventotene and Ponza, as well as some 

 places round Capri, the Blue Grotto, the Siren Islands, and some grottos 

 at Amalfi. These explorations are continued as often as the weather 

 permits. 



Practice and experience have enabled several improvements to be 

 effected ; and, indeed, much more depends upon the successfal manage- 

 ment of the diving apparatus than upon the possession of the apparatus 

 itself. 



It is of primary importance that the diver should be a strong man, 

 able to carry, when out of water, his 165 lbs. — the weight of the dress 

 and its appurtenances. This is a factor upon which so much rests that 

 it needs especial notice. In water, however, the apparatus becomes 

 naturally lighter to carry the deeper the diver proceeds, and even in 

 four or five fathoms he is able to move about quite conveniently with 

 it. Por the satisfactory attainment by diving of the objects of a zoologist 

 or botanist, free movement on the sea-floor is unquestionably a sine 

 qua non. 



The mere fact of descending or of being let down is comparatively 

 unproductive if the diver is not able to seek out special localities where 

 animal and plant life is richest and most varied ; and he would even be 

 led to conclude that uniformity of character exists on the sea-floor. In 

 order that the diver may move about freely and without impediment, the 

 boat which carries the air-pump must always follow his course, — this 

 being shown by the bubbles of air which ascend from the helmet and 

 are continually bursting on the surface of the water. The diving-boat 

 should be large and strong, and will require the following complement. 

 Two men for rowing, two for keeping the pump continually in motion, 

 and, as this is fatiguing work, it will be desirable to carry an extra man 

 as relief, especially if more than one person is diving ; whilst another 

 man, making five or six in all, is needed to attend to the diver's signal 

 rope, for the purpose of communication, — the signs being given by puUing 

 or jerking at this rope. For further convenience, it is desirable to have 

 a small jolly-boat near by, canning tubs and buckets for the reception 

 of the stones, rock-fragments, or other booty which the diver sends up 

 in the net or fish-basket which is let down to him repeatedly. The diver 

 himself is armed with hammer and chisel, and will be able, if only 

 cautious that none of the glasses in his helmet are broken accidentally, 

 to remain an hour or two at the bottom of the sea, according as he may 

 wish or as his powers last. Currents are his greatest enemy, and these 

 are sometimes so strong as to knock the diver down, or if within reach 

 of the action of the waves he may be pitched about hither and thither 



