78 On Gun Cotton as an Explosive Agent. 



The buckets are fixed to the chain web G at eveiy alter- 

 nate hinged portion, as shown. This chain is composed of a 

 series' of plates with joints projecting internally to gear 

 in with corresponding indentations in the angles of the 

 octagonal revolving drums H and J above and below and 

 round which the chain-web passes. 



The framing carrying these drums may be mounted on 

 the lower tank K ; the buckets, as they revolve, empty 

 themselves into this tank, which is kept constantly full of 

 water to the level of the overflow L. 



The shaft M, on which the drum is keyed, transmits the 

 power for driving the clock, &c., the pendulum of which 

 regulates the descent of the full buckets in the same manner 

 as with an ordinary weight. 



This apparatus can be kept at any reasonable distance 

 from the clock, above or under it, or in the corner of the 

 clock -room itself, as circumstances may best determine, and 

 when once set going, will continue as long as the materials 

 last and the water is supplied. 



The plan now exhibited is for driving the works of a 

 large clock, such as that required at the Town Hall. A 

 slight modification of this plan would also adapt it to 

 striking hours and chimes. 



As before stated, this system of weights would be self- 

 acting, so long as the supply of water was continued ; but 

 as street-mains ai'e liable to contingencies, I have, in order 

 to make this scheme thoroughly complete, introduced a 

 small force-pump N between the two cisterns A and K ; and, 

 as the cistern K is kept full up to the level of the overflow, 

 all that would be required in the event of the street-main 

 being under repair, would be to pump the water from K to 

 A until such repairs were effected. 



There are no cities or towns of any note in the Austra- 

 lasian colonies without a high-pressure water supply fitted 

 for the purpose I have here described. 



Art. XXIV. — On Gun Cotton as an Explosive Agent. By 

 R L. J. Ellery, Esq., F.R.C.S. 



[Read 12th June, 1871.] 



In this paper the President gave a brief account of the 

 properties and manufacture of gun cotton, with a few 

 illustrative experiments. 



