Revieivs — Catalogue of Minerals, South Australia. 473 



me a copy of their highly interesting and elaborate paper (Journal 

 Geological Society, London, 1891, p. 198, and 1892, p. 170), 

 which showed that there was a remarkable similarity between the 

 rocks of Barbados and those of Naparima. But it was not even then, 

 but a couple of years later, that I became aware of the existence of 

 cement-producing materials in the oceanic rocks of Barbados similar 

 to those of Naparima. Professor Harrison had the kindness to send 

 me, what I had not seen before, a copy of the report prepared by him 

 in conjunction with Mr. Jukes-Browne on the geology of Barbados 

 for the Government of that island. In this they say : — 



" The lowest chalky beds of the oceanic series possess a value 

 which is derived partly from their chemical composition and partly 

 from the fact of their lying immediately upon the dark clays. In 

 these deposits we have the materials for the manufacture of cement. 

 We believe the cement-making will be, if the suggestion is followed 

 up with energy, one of the most promising of the industries of the 

 island. We may mention that there are other beds of chalky earth 

 which would be equally suitable for the manufacture of cement, and, 

 further, that there are beds of dark-grey earth consisting partly of 

 chalky earth and partly of fine mud, which have a chemical com- 

 position that seems to indicate their suitability for making cement 

 without any admixture of clay." 



Beds of the identical composition of those referred to in the fore- 

 going extract occur in the Naparima district. It is matter for trial 

 and experiment merely which of them is best for the manufacture of 

 cement. My own opinion is that the softer beds will be the best, but 

 some of them may require to be mixed with more argillaceous material, 

 which can easily be obtained from the other beds in the neighbourhood. 

 It is probable, however, that a material will be found which will give 

 the right proportions without any admixture. 



During my investigation of the Naparima rocks, particularly in 

 1891, I was struck by the remarkable resemblance in composition 

 between these rocks and those from which cement was manufactured 

 as described by various authorities. I have not at present by me all 

 the works I have consulted on the subject, but it will suffice to refer 

 to the United States Geological Reports, namely, the 20th Annual 

 Report (1898-9), the 21st Annual Report (1899-1900), p. 402, and 

 the 22nd Annual Report (1900-1), p. 728. According to these 

 the average composition of the material for the best quality of cement 

 is practically the same as found in the Naparima deposits. 



IS E -V I E "VvT S 



I. — Catalogtte of Minerals ix the Technological Museum op the 

 South Austkalian School of Mines and Industries. Compiled 

 by Herbert Basedow, Honorary Curator, pp. 200. Adelaide : 

 C. E. Bristow, 1907. 



IT is evident from the Catalogue which has been carefully prepared 

 by Mr. Basedow that the South Australian School of Mines 

 possesses a collection of minerals well adapted to the purposes of 



