Vol. XIV. No. 348. 



TI1K AGRICULTURAL NEWS 





WATER-SUPPLY. 



HYDRAULIC RAMS. 



On some estates in the VV< si Indies the installation 

 of a hydraulic ram for raising hei for domestii us< 



might I"- ec mically applied. Estate houses an 



often erected ai a considerable elevation above their 

 watei supply, and where this occurs it necessitates some 

 form of pumping, others ise the water has to be carted 

 or carried by hand. The folio wii ful article on the 



hydraulic ram- i- reproduced fr the Rhodesia Agri- 

 cultural Journal- 



Wherever .1 fall of water is obtainable, either from 

 a running stream, a dam or other source of supply, a h 

 He ram can be operated. The principles of working 

 a hydraulic ram are simple; the) depend upon the utilization 

 of the momentum of falling water. 



Looking at the sketch here reproduced, if control valve 

 'V is opened, the water will fall down the drive pipe 'S' and 

 escape at valve 'W until it has attained sufficient momentum 

 when valve 'W will close. The impulseor momentum of the 

 stream thus attained forces the water through valve 'R' into 



the ail 1 h im n c V and up the di > • \ - 'I ' until this 



momentum ceases, when valve 'W opens and valve 'I! closi s 

 and retain- this water in the delivery pipe '|i. Again, when 

 valve 'W '.pen- the watei lown delivery pipe 'S' until 



it again attains sufficient momentum, when valve 'W closes 

 and a further quantity of water is forced through valve 

 'R' up the delivery pipe '] »' Tins cycle continues automatic- 

 ally, and in this manners certain percentage of the drive 

 water is raised to a greater height than that of the sun 

 the supply water le\ 



1 1, ■ tjgha 1 



Iraulic rams vary (a it to 70 pei 



ling to the maki 1 .1 the ratio of the fall to the 



lift. Tin- does not include tl >n in the 



which will varj direct! i l, and 



inversely as the square of it er. This means that 



one quarter to seven tent I k actually done 



is usefully performed in the delivery of the wati r, 



( lenerally spe ikii f fall to lift i 



whilst ratio 1 20 are quite workabL 



types of rams. Outside of these ratios the rams an 



expensive, and fo I ratios are le-s efficient. T 



a ratio of L:10 as shown on the sketch, viz., a I ill and 



a lin'ert lift, and with a supplj "I driving watei 



Ion pei minute, a 1 im would in theorj 

 delivering 2 ' gallons per minute. The probable effii 

 with this ratio would be ib ml 10 per cent., and that 1 

 the actual quantity oi wu red 03 the ram would be 



US per minute. 



ram, 

 his 



ii is absolutely :essary te 



agents with the following 



about I |1 



Before ordering 

 supply the maker 

 particulars: 



1 l 1 The vertical fall in feet or inches which is 

 obtainable from the source of supply. This working fall 

 should be measured as shown on the -ketch from the 1 

 supply water level to such a level that escape valvi 

 would have a free nutlet. 



Tic vertical height to which the w iter h 

 raised above the level of the ram. 



(3) The length of the delivery pipe required. 

 ; I ) The approximate quantity of drive water, m< 

 in gallons per minute, which is available. Methods for the 

 ia of (lowing water are described in Bulletin 

 \". til of February 1911, issued by the Department of 

 ill ere, Salisbury . 



(5) The number of gallons it is desired to' raise in 

 a day of twenty-four hours. 



(6) The length of supply pipe that is try. (This 

 should be kept as short as possible.) 



It will be obvious that only in rare instances will all 

 these conditions be the same in each case; for instance, there 

 maybe a large quantity of drive water, low fall, and medium 

 lift, and in another case a small quantity of drive water, high 

 fall and high lift, and all othpr various combinations. Thi re 

 fore it is most important when ordering a ram to supply the 

 makers or their agents with full particulars as mei 

 a 1 11 w e. 



Fig. 



I liagrammatic Sectl m fa-] [ydraulic flam. 



In theory the principle maj be explained thus: It'll) 

 gallon- of water fall I" feet high in I minute, they would be 

 capable of rai tag I a A water per minute 1 00 feet high, 



because 10 gallons ■ I' 1 feel c, e,,|- 1 gallon x 100 feet in 

 gallon feel allons of water fall 5 feet they 



would be capa 1 gallons 1 00 feet, because 100 



x 5 feet equal 1 I""- But in practice these 



results are not obtainable, as we have to allow for the friction 



in the drive and delivery pipes, the slipping and friCti t 



the valves, and the less of water which i iry for the 



operation oi the ram. Many makers claim high efficiencies, 

 but in .1 number of c ieneies are obtained under 



ideal tost iditions, and it will accordingly be as well not to 



During the night 'it August 10 a heavj gale passed ovei 



Dominica which caused a a I deal ol damage in the B 



Gardens. About 100 trees, some of lai havi 



uprooted or damaged, and a number of species of rare trees 

 of which there was onlj a -ingle specimen ha en lost. 



In the south of the island damage was caused by the wind 

 from the southeast, which commenced to blow about (i in the 

 evening. Many of the exposed estate- losl a number of trees 

 together with a considerable portion ol the lime crop. In 

 some cases the loss i- covered by insurance. In regard to the 

 Gardens, a special grant oi £30 has been obtained to assist in 



0g away the refuse, the extent of which is very vividly 



n by a series of photographs forwarded bj Mr. June-. 

 the Curator. In connexion with the foregoing inform 



ditorial in this issue dealing with storm-damaged crops 

 will be read with interest. 



