ON SELF-ACTING INTERMITTENT SirHOSS, ETC. 223 



Second Report of the Committee, consisting of Dr. A. W.William- 

 son, Professor Sir William Thomson, Mr. Beamwell (Secretary), 

 Mr. St. John Vincent Day, Dr. C. W. Siemens, Mr. C. W. Merbi- 

 field, Dr. Neilson Hancock, Professor Abel, Mr. J. R. Napier, 

 Captain Douglas G-alton, Mr. Newmarch, Mr. E. H. Carbutt, 

 Mr. Macrory, and Mr. H. Trdeman Wood, appointed for the 

 purpose of watching and reporting to the Council on Patent 

 Legislation. 



The Committee have to report that they have held several meetings, at 

 which they prepared a memorial upon the Bill for the Amendment of the 

 Patent Laws, brought in by the Home Secretary and the Attorney- 

 General. 



This memorial is printed as an appendix to the Report of the Council, 



p. lxiii. 



The memorial was presented to the Attorney-General by a deputation 

 from the Council of the Association on the 17th of May last. 



The bill became a lapsed order ; but the Committee have every reason 

 to hope that their recommendations will be duly considered if a similar 

 measure should be introduced in the next or any future session. 



On Self-acting Intermittent Siphons and the Conditions which 

 Determine the Commencement of their Action. By Rogers 

 Field, B.A., M. Inst. C.E. 



I A communication ordered by the General Committee to be printed in externa 



among the Reports.] 



In the discussion on Mr. Barlow's paper on the upward jets of Niagara, 

 read at the Plymouth meeting of the Association, I made a few remarks 

 with reference to an improved form of self-acting siphon I had invented, 

 the action of which depends on the power of falling water to drag air 

 alono- with it, and I now, by request, will give a description of the action 

 of this siphon illustrated by a working model. 



Before proceeding to describe the peculiarities of this siphon, it will 

 be well to say a few words generally as to self-acting siphons employed 

 for the intermittent discharge of fluids from vessels. The idea of em- 

 ploying siphons in this way is by no means new, and I may instance the 

 philosophical toy, called ' Tantalus's cup,' which many of us have seen 

 in our youth. In this cup there is a concealed siphon, which is brought 

 into action when the cup is raised to the mouth to drink, so that the 

 water sinks away from the lips and cannot be drunk. A self-acting 

 siphon has also been employed for emptying vessels used for measuring 

 water, as in Osier's and Bickley's self-recording rain gauges, as well as 

 on a large scale for reservoirs. 



The chief difficulty to be overcome in applying siphons in this way 

 is to start them or pnt them in action. In an ordinary siphon, such 

 as that shown in fig. 1, the siphon will not be put in action unless the 



