Retepora. 13 



are in one piece, and go directly deep into the earth, as the 

 making and keeping up good sound metallic joints will be 

 found a difficulty in practice. 



An independent conductor carried as direct to the earth 

 as possible will be found the least expensive in the long run. 

 Never take the conductors inside the buildings for the sake 

 of short cuts, or for any reason except where a more rapid 

 and extensive earth connection can be obtained by doing so, 

 than otherwise. 



Lightning conductors, as commonly arranged, are in most 

 cases very far from ornamental additions to the buildings 

 which they protect ; the use of vanes, pinnacles, ridging, 

 and other external metallic details of a building to form 

 portion of the conducting system has the recommendation 

 of being less objectionable in an sesthetical sense than 

 the form of lightning-rods wholely extrinsic to the 

 design, as commonly employed ; and, by a little judicious 

 management the ornamental terminations of gables, roof, 

 towers, and turrets, may be made to entirely and very 

 effectually subserve the requirements of a lightning pro- 

 tector by keeping in view the foregoing suggestions. 



Art. V. — Contaminated Water Supply. By S. W. Gibbons. 



[Bead 13th October, 1873.] 



Art. VI. — EckhoMs Omnimeter. By R L. J. Ellery. 



[Bead 13th October, 1873.] 



Art. VII. — On the Occurrence of a species of Retepora 

 (allied to R. phcenicea, Busk), in the tertiary beds of 

 Schnapper Point, Hobsons Bay. 



By R Etheridge, Jun., F.G.S., 



(Of the late Geological Survey of Victoria). 

 [Read 13th October, 1873.] 



When examining for Foraminifera, portions of the light 

 grey mad from the Eocene or Oligocene beds of Schnapper 

 Point, the accidental fracture of a large mass revealed 



