Ixxxv 



1 Ephthianura albifrons. 

 1 Meliornis novce-hoUandite. 



1 Selby's Thrush, Colluricincla Selbii, by Mr. H. L. Swift. 

 1 Firetail Finch, Estrelda beUus. 

 1 Striated Calamanthus, Calamanthus fuliginosus. 

 1 Yellow-throated honeyeater, Ptilotis flavigula. 

 1 Dusky Robin, Petroica fusca. 



1 Pink breasted Robin, Erythrodryas rhodinogaster. 

 1 Flame breasted Robin, Petrceca phcenicea. 



1 Blackcapped honeyeater, melithreptus melanocephalus, by Mr. F. 

 P. Wilson. 

 A collection of Tasmanian Birds' Xests, Mr. J. R. McClymont, M.A. 



MoUusca. 

 Tasmanian Shells, Mr. E. D. Swan. 



Ethnology. 

 A Fijian Native Basket, Mr. E. D. Swan. 



.SUBMARIXE CABLES. 



The Hox. Secretary (Hon. Dr. Agnew) announced that Mr. Pv,obt. 

 Henry, jun., Superintendent of Telegraphs in Tasmania, had promised 

 to deliver a lecture on " Submarine Cables," giving a practical illustra- 

 tion of the means by Avhich the localities of breaks or faults in the cable 

 are determined. 



Mr. Hexry prefaced his remarks by describing the manner in 

 which cables are const.'ucted and the materials and process used to 

 ensure complete insulation, not forgetting the spiral covering of brass 

 ^yhich is sometimes necessary in Indian seas to protect the cable from 

 the ravages of a specie of Teredo, which bore through the gutta- 

 percha covering till the copper case is reached, then destroying 

 the insulation. To illustrate his remarks on the preservation of cables, 

 he exhibited a small section of cable cut from the break which recently 

 occurred between Tasmania and Victoria, about 70 miles from Low 

 Head. The present cable had been down about 15 years, and this was 

 about the only serious break that had occurred. There had been one or 

 two breaks previously, but they had been nearer the shore, and the causes 

 had been apparent. At the Victorian end a reef of reck ran across the 

 cable, and could not be avoided, and the result was that in time the cable 

 was fretted away by the continual action of the waves. About five years 

 ago, however, a heavier cable had been laid at the shore ends, and no 

 troul)le from that quarter had arisen since. The lecturer then proceeded 

 to explain the different conducting properties and resisting powers of 

 the various metals, and showed a small coil of German silver— a very bad 

 conductor — which had a resistance equal to 50 miles of cable. He entered 

 at length into a description of the means by which a current of electricity 

 may be used to measure lengths of wire. There were two units of 

 measurements, called "ohms," in general use; one, the "British Associa- 

 tion unit," might be roughly represented by a mile of copper wire about 

 one-quarter of an inch in diameter, and the other, " Siemen's unit," 

 represented by a column of pure mercury about forty inches in length 

 and l-iOth of an inch in diameter. The " ohm " must be understood to 

 represent a standard of comparison, in the same manner as an inch in 

 length or an ounce in weight, and it was evident that having once fixed 

 a standard it was easy to compare results with other lengths and descrip- 

 tion of wires, and therefore made it possible to determine the resistance 

 of any length of cable. In the resistance-box shown were a number of 

 small coils of wire, which, though they appeared to be of the same size, 

 represented very different values, one of them being one " ohm," and 



