Nov, 2, 1885.] 



THE TROPICAL AGRICULTURIST. 



321 



(fiovrespondenoe. 



To the Editor of the " Oetjloa Observer." 

 CITRONS. 



Prince of Wales' College, Moratuwa, 27th Aug. 1885. 



De.u! Sir, -I read with interest the communic- 

 ations which appeared in your valuable journal 

 on the subject of tlie culture of lemons in Ceylon, 

 and now take the liberty of sending you per train 

 a tew specimens of the fruit grown here from a 

 cutting sent to me by Mr. Fonseka of Pittagon 

 Eliya estate. Kaliitara. Please let me know your 

 opinion of them. Crops of from twenty to forty 

 are plucked each season. I have seen the parent 

 tree in Kahitara in a most thriving condition.— I 

 remain, yours faithfully, 



W. S. GOONEWAEDENE. 



[We regret that this letter should have been 

 overloolced. The fruits sent were not true lemons, 

 but " citrons," which are less juicy and much more 

 thick-skinned. A preserve is made of the citron 

 skins, but the fruit is less valuable than tlie 

 lemon. — Ed.] 



BAELET GROWN ON UVA PATANA LAND. 



15th September 1885. 



Deab Sir, — By this post I am sending you a sample 

 of barley grown on Uva patana land, at .\lbion. The 

 seed was sent to me by the Murree Brewery Company, 

 but did arrive in Colombo till late in .January, and the 

 dry weather setting in so soon after it was sown was 

 very much against the experiment proving the success 

 I believe it would have been, had the seed been 

 available tor sowing in December. As it is I only 

 got about the same quantity that was sown, but 

 being only a small patch the rats and fowls 

 from the lines did a lot of damage before it was 

 ripe, and it suffered very much from drought. — Yours 

 faithfully, ARTHUR J, KELLOW. 



WATER-POWER ON TEA ESTATES. 

 Matale, 10th Sept. 



SiE, — The enclosed simple directions for ascertain- 

 ing the quantity of water available from any given 

 stream may, perhaps, be of service to your corre- 

 spondent " Planter, No Engineer," and to others. 

 —Yours faithfully, R. R. 



Turbine wheels have gone into such general use in 

 this country that an overshot whci'l is now very seldom 

 seen. The turbine is so much cheajier nnd so much 

 easier to set up and manage tliat it is generally pre- 

 ferred wherever its merits are kuiwu; but in tropical 

 countries the turbine has not yet become very much 

 known and is little understood. It is a very" simple 

 wheel to understand and manage, and in many local- 

 ities is by all odds the best wheel that t^au be used. 

 The turbine can be used anywhere that an overshot 

 can be used, and in many places where an overshot 

 would be practically out of the question. For high 

 heads and a comparatively small quantity of water the 

 turbine is the only wheel fit to be used. 



We frequently n-ceive inquiries and orders for wheels 

 without any data being given to enable us to judge 

 the kind or size of wheel needed. For instance, a 

 planter will order a certain sized sugar mill "with 

 a water wheel of the proper size to drive it," with- 

 out giving us any intimation of the quantity of water 

 or the height of fall. As a large quantity of wnter 

 and low head requires an entirely ditierent wheel from 

 a Bmall quantity of water nud a high head, we are, 

 of coursp, unable to build tlte wheel until wc are furn- 

 ished with tlie^e data. They should always be given by 

 those iuquiriiig about or ordering a wheel. The quant- 

 ity of water in a large, open stre;\m can be ascertained 

 with sufticient accuracy by giving the velocity of the 

 water, and the area of a cross section in square feet, 

 41 



The velocity may be estimated by throwing a float- 

 ing body on the surface and noting the time required 

 in passing a given distance. The area of cross seofion 

 may be ascertained 'jy measuring the average 

 depth and width of the stream. F.ir smaller streams 

 the wier dam measurement, as illustrated on a follow- 

 ing page, is best. It is always well to send us a 

 rough sketch of the stream and ground where the wheel 

 is tea be located and inform us on which side of the 

 stream the machinery is to be located. In ordering 

 turbines state which way they must run, whether with ' 

 the sun, that is from east to wept ou the south 

 side or against the suu, that is from w st to east on 

 the soutli side; the former is sometimes called I'iKht- 

 handed and the latter left-handed. 



To construct a weir dam for the purpose of measur- 

 ing the water, a single board or plank, long enough 

 to reach across the stream and rest in the bank at 

 each end, should have a notch cut in it about two- 

 thirds the width of the stream, and deep enough to 

 pass all the water to be measured. The bottmn and 

 ends of the notch should he bevelled ou the down- 

 stream side, so as to pass the water freely ; then go 

 several fe't up strream and diive the stake E iu the 

 bottom of the stream till the top of the stake is on 

 a levil with the water when it first begins to spill 

 over the bottom of the nutch iu the weir dam. When 

 the water has readied its height, and a full volume 

 is pouring through the notch, the depth of the water 

 iibove tlio top of the stake B can be easily measured 

 as shown in the engraving, .and will give the length 

 of the line C D or the depth of the water passing 

 over the dam. Then knowing the length of the notch 

 A C by referring to the table on the next page the 

 nunjh^i of cubic feet iier minute passing over the dam 

 can be ascertained. The height of the fall cm be 

 ascertained by measuring from the surface of the water 

 below the fall to the level of the surface above the 

 fall, as shown by the line E in the engraving. Then 

 in writing to us give us the depth of the water over 

 the top of the stake B, or in other words the length 

 of the lino C D. als ■ the length of the notch "w the 

 line A C, also the height of the fall on the line E, 

 and we can then easily determine the size of wheel 

 needed. 



[Unfortunately we cannot reproduce the sketch 

 of the waterfall, etc., hut our corresf ondent, who 

 does not give his full address, has forgotten to 

 send the table referred to. We have further letters 

 with useful information on tliis subject to publish. 

 —Ed.] 



DO. USEFUL FORMUL.E. 



Colombo, 19th Sept. IS85. 



De.ir Sib, — In reading the communication of 

 " R. R." in your issue of last night one is impressed 

 with the idea that something more complete and 

 more concise is wanted as an aid to planters in 

 estimating the power residing in their streams. 



Construct a temijorary sluice with square sides 

 (for small streams an old door with a panel knocked 

 out will do), place it on the brink of the fall, direct 

 all the water through the aperture and lower the 

 slide until it is skimming the surface, then measure 

 the opening and multiply its area in feet by the 

 square root of the height in feet and by 2111 ; the 

 result will be cubic feet of water discharged per 

 minute. 



Suppose a sluice is set as above described passing 

 all the water a stream supplies and the aperture 

 measures 1 ft. 3 in. wide by 1 ft. 3 in. high, then, 



Area Sq. root of height 

 in sq. ft. in ft. 



1.5() X 1-12 X 210 = 377 cub. feet 



water discharged per minute, nearly. The approx- 

 imate h. p. will be found by multiplying the cub 

 feel water by the height iu feet of the fall and 



