TRANSACTIONS OF THE SECTIONS, 229 



On Mechanical Siolcing. B>j James Smith, 



On a New Safety -lamp. By W, E. Teale, 



Bescnjption of the Hydraulic Bucletting -engine for the Ilerculaneuni 

 Gi'aving-docl; Liverpool. By Percy Westmacott, C.E, 



The application of hj'draulic power to gates and capstans &c. having already been 

 decided upon for these docks, it was considered expedient to contrive the emptying of 

 the graving-docks in conjunction with this same system, and thus save the erection 

 of another steam-engine and plant for this special service, and at the same time secure 

 a ready means of applying power at all times, especially to severe leaks. Some ar- 

 rangement, too, was required that would overcome the inconveniences experienced 

 in dealing with water charged with rubbish from graving-docks. The result was tho 

 construction of a machine upon a principle of buckettiug large quantities of water 

 at a time — devoid of clack-valves, gi-atings, or other parts liable to choking or in- 

 juiy by floating matter, and that could be lifted clean out of the water to give free 

 access to all parts when required. By this principle the same weight of water is 

 discharged at each stroke, and thus no undue loss arises from the application of a 

 constant hydraulic pressure ; nor does the strain upon the parts or the conditions in 

 working varj^ with the fall of water in tlie dock. A scooped-shaped bucket at- 

 tached to a piston-rod is plunged at an angle of slight resistance into the water, and 

 by a self-acting arrangement is turned round at the 'proper level, filled, raised, and 

 discharged over an apron. The bucket holds 14^ tons ot water. Two discharging- 

 levels are provided. 



It will be seen that when the bucket is up all essential working parts are out 

 of the water, and therefore quite free of access. 



The minimum lift at the high-level discharge is 7 ft., and the maximtim 23 ft. 



The usual average speed of the bucket in plunging or lifting is about 3 ft. per 

 second. 



The coefficient of effect obtained by this engine is as follows : — At 7 ft. (mini- 

 mum) lift -4 ; at 23 ft. (maxinnmi) lift '6 ; average -54. Tlie loss occasioned by 

 the choking of passages and gagging of valves or paddles is altogether avoided by 

 this system, which, for this reason, is peculiarly Avell adapted for sewerage purposes. 



On Street Managevunt. By F. "WiLSOjr. 



APPENDIX. 



On the Ver/etahle Products of Central Africa. 

 By Lieiit.-Colonel J. A. Geant, C.B., F.L.S. 



The country embraced in the remarks made by the author comprises that tra- 

 versed by the late Captain Speke in his journey to the sources of the Nile, 18C0-()3. 

 The plants collected were made over to the Royal Herbarium, Kew, and were 

 classified there by Dr. T. Thomson. They are to be described in the 'African 

 Flora ' by Professors Oliver, Lawson, ^Masters, and others. Notes and drawings 

 of the majority of tho specimens were made on the spot, and from these notes the 

 author had compiled this paper. He described, in the first place, the forests of 

 the low lands, which consist of trees which are commercially of small importance. 

 The species are numerous, and for nearly all of them tlie natives seem to hti\o 

 names. The author then described at considerable leugtli the uses made by the 

 natives of the roots, bark, leaves, fruits, seeds, and grains of numerous trees, shrubs, 

 and plants as medicines, foods, houseliold utensils, fishing-implements, and tho 

 like. 



