Clock for the General Post Office. 75 



thing more than the absence of crystalline forms in their 

 entirety — or the rolled and water- worn appearances in this 

 Berwick discovery. They differ wholly from any I have 

 seen heretofore. There is no sign of their being water- 

 worn ; and where a piece shows a solid angle, or where a crys- 

 tal is complete — as a few of the blue sapphires, rubies, and 

 one or two of the Oriental amethysts are — it is most perfect. 

 The characteristic appearance of the collection, taken as a 

 whole, is that of splinters — as if they had been broken with 

 violence out of the hard formation that originally contained 

 them — and that they had been left ever since in a state of 

 quiescence. Ordinarily speaking, I should say they cannot 

 have been washed very far from their original situs. And 

 the granite formation and the old basalt through which the 

 Berwick Creek and its tributaries flow would seem to be 

 their native home. No doubt ere long much more will be 

 heard about both the district and its gem beds. 



Art. XL — Description of a Clock made for the Lobby 

 of the General Post Office, Melbourne. By Mr. R L. J. 

 Ellert, (Government Astronomer), President. 



The President gave a description of a new clock he had 

 designed for the lobby of the new Post Office, and which 

 had lately been constructed by Mr. Gaunt of this city. The 

 clock has two dials, one in the lobby over the centre of the 

 staircase, which was four feet diameter, and showed a seconds 

 hand as well as hour and minutes hands ; the second dial 

 was in the great hall, and had a smaller dial showing no 

 seconds hands, the leading off or connecting shaft being 

 carried through the wall dividing the lobby from the hall. 



The chief features of interest were the escapement and the 

 excellent and workmanlike manner with which the works 

 have been constructed, more especially as the requirements 

 rendered a peculiar arrangements of parts necessary. The 

 escapement was that known as Denison's detached gravity 

 Bemontoire which possesses the great advantage of always 

 giving exactly the same impulse to the pendulum independ- 

 ant of any irregularities of the friction of the train, and in 

 fact renders any great finish or precision of the train un- 

 necessary. 



