Sessional_Paper_1907 — Page 453

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A.-

We have it now, but we treat it as an adulterant,-the Canton lime that comes down from the North, rather from the Pearl River, not the West River.

Q.-Stone lime, are you speaking of?

A.-No, it is supposed to be oyster shell lime. I am not speaking of my own know- ledge, but of what is told me by the contractors. They constantly bring this lime here. It is not white, it is a yellowish colour, and our tests of that lime go to shew that it is adulterated with a very large proportion of white clay, and we are unable to get that lime to set at all. We have tried it with sand and red earth of various kinds.

The Chairman. Is it ever adulterated with clay ?

A.-My opinion is that it is about 75 per cent. of clay, and 25 per cent. of oyster shell lime, so that I am not very much in favour of using any local puzzolana or clay, with a view to assisting in slaking the lime. The lime reaches us practically slaked.

Mr. Shelton Hooper.-Now, the ordinary lime concrete made here with red earth, there is a certain amount of hydraulicity in the red carth, isn't there?

A. Yes, in some kinds of red earth.

Q. In the majority of red earths. And haven't you seen, digging up old works, some floors in which the lime concrete has been perfectly good and satisfactory to you?

A. Yes.

Q-Therefore it shews that it has been possible, that is what I mean,—to make a good lime concrete with materials which we have at hand here?

A.-Oh yes, I have made myself in my own experience, plenty of good lime concrete that has set extremely well, and I know of large blocks at the present moment that are old lime concrete, and that are quite good.

Q.-Now, taking into account,-which is a very important thing for the public health,- the enormous increase in the cost by using cement instead of lime for concrete, which it would entail, can you make any suggestions for a good lime concrete which would serve the purpose, and still be as cheap ?

A. Yes I can.

Q-What would you suggest?

A-I would suggest that the material brought into this Colony be more or less policed, if it were possible. That a junk of bad lime that comes to the Praya to one of my jobs that is sent away, should never be allowed to get into the harbour. If it were possible to make it contraband-it is rather Utopian,-but given a lime which does not contain more than a certain percentage of adulteration,-the common adulterant is sand, given a red .carth of a proper quality, and clean broken granite, and mix these three in the correct proportions with the correct amount of water, I will undertake to make you a lime concrete that will set.

Q. And you could do that much cheaper, than with cement?

A.-Ol: yes.

Q-Now with regard to floors,-I dont know if they are in the habit of doing it here, wouldn't it improve it very much indeed if they were to ram it down, until the lime comes to the surface ?