566 



THE TROPICAL AGRICULTURIST. 



[February r, 1884. 



Machine, we had ou Kellie estate, to do its work 

 very well indeed. It makes a good, even roll, giving 

 the leaf a good twist, and does not break the leaf 

 80 much as some other machines in use. The quantity 

 of work I could get out of the machine was about 

 200 lb. of withered leaf per hour. I have no hisitatica 

 in recommnidinc! the machine for the quality of the 

 work that it do'S." 



We have in stock several of Messrs. Greig & Co. 3 

 machines for hand, steam I'r water- power-, and shall 

 be happv to give full particulars of s.ame on applic- 

 ation.— Yours faithfully, W. H. PAVIES & Co. 



MR. W. CAMRRON'S CINCHONA AND TEA 

 D FLYING APPARATUS. 



Deak Sib— I have been glancing over Cameron's 

 plans of a " bark drier, " and his remarks there- 

 upon. It seems to me that he is out in his views 

 on one or two particulars ; a^ul, as th« subject is of 

 importauce to planters at present, I need no apology, 

 I think, in showing where I believe he is mistaken. 



1st. Regarding the comparative merits of iron and 



brick as a heater, he says som.^tliing about iron giving 

 out heat by radiation, and brick by conduction. I 

 think he is wrong in that : I would say it is the 

 other way. However, the chief point regarding their 

 respective merits is, that the conductuity of iron 

 compared to brick clay is about 30 to 1. Con- 

 sequently a flue of clay, to extract from the tire the 

 same amount of heat as an iron flue, would have to 

 present a surface 30 times as large. For economy of 

 space, therefore, iron is preferable. 



2nd It is hardly correct to say that the limit of 



heat extracted from the lire is merely • ' that sufficient 

 hi- left to take the finoke up the chimney." In a long 

 flue, for example, near the fire it is being heated up 

 to. say, 600°, that is, the flue takes out the heat at 

 600° ; a little furthe- from the fire, it takes it out at 

 400, then at 300, "00, 100 and so on. Now if you 

 want to use heat (say heated air) at 4'i0. all that is 

 taken out at a lower temperature than 400 will not 

 raise the temperature of your heated air, but lower 

 it. Therefore, tlie limit of the amount, of heat you 

 extract from a tire, is the temperature you wish to 

 use the heat at. If you wish 4nO, it is 400 or a 

 little over 400, as you must allow for waste in transfer. 

 All below 400 must be disp-.sed of up the chimney. 

 For quick reception, and quick giving out of heat, at 

 high temperatures, metal has the advantage. Copper 

 ie about three times as yood as iron, so copper is 

 used in the flue tubes of boilers. 



3ri^. — Mr. Cameron eeema hardly to have under- 

 stood the " Clerihew," and so has failed to see one 

 very important particular in which it has an ad- 

 vantage oviT his methol. 



When hot air comes in contact with moisture, the 

 water is evaporated, taking from the hot air its heat 

 to efifeot the evaporation ; consequently the air gets 

 cooler, and with its moisture tends to descend. In 

 Cameron's drier, this result may be expected. The 

 hot air finds it.s way up thr<>ugli among the bark, 

 what of it is effectual iu drying bnrk gets heavier 

 by the process and tends to co down ag'iin, to get 

 reheated before it ascends. But altbjiugh it may be 

 reheatpd, it is not ao good for drying as fresh un- 

 moistured air. Also .any portion of the originally heated 

 air that escapes without moisture rises and passes off 

 uselessly. By reversing the process, and sending the 

 dry air in above the bark and drawing the heavy 

 moist air that has done its work out below, only used 

 air is removed, and all the drj' air has to do its 

 work. If he would reversi" his process in accordance 

 with this, he would find his drying not by half so 

 expensiV'-. 



For want of observing this, he has failed to com- 



prehend the principle of the "Clerihew." The fani" 

 the '• Clerihew " is not to he'p the air-pressure result- 

 ing from the heated air, but to overcome it. In the 

 " Clerihew," the air, after being heated, ascends by 

 a flue to the upper story, being raised by the greater 

 pressure of the external air, of course. To overcome 

 this pressure and draw the heated air down, the fan 

 is used, having its place below the floor, or if there 

 be more than one floor below the floors, of the air- 

 tight room. Thus drawn down through the coffee, tea, 

 bark, or whatever is a-drying, all the good of the 

 heated air is taken out of it. I do not quite under- 

 st ind his system of shelves movable and otherwise. 

 I observe he states what is very true, "that the air 

 will go through where it can get easiest. Therefore 

 any hole would allow air to pass, and so go to waste. 

 A large hole would let all the air pass, so that, it 

 seems to me, tue movable trays would be a mistake, 

 as when removed, all the rest of them would be use- 

 less till the movable one was restored to action. Even 

 any inequality in the thickness of the coffee, &c., spread 

 over the floor is a disadvantage, as the greater quantity 

 of heated air would pass through the thin-spread, 

 where there was least required. Such are a few 

 )ioiuts that seemed to me to be defecis in Mr. 

 Cameron's plans. I send them to you, that the judges 

 may take them for what they are worth.— Y'ours truly, 



J. B. 

 [We find that it will be impossible for us to re- 

 produce the plans. — Ed.] 



SUGAR CULTIVATION IN CEYLON. 



Kandy, 26th Jan. 1884. 



De.\r Sir, — 1 have lately noticed a letter in yciur 

 paper relating to the cultivation of sugar in Ceylon. 

 Some years ago I had occasion to investigate the 

 circumstances under which sugar hss been successfully 

 cultivated iu Australia. 



With a view to reopening the subject of its cultivation 

 in Ceylon, I may state, that I then heard from a 

 good authority, an Australian sugar planter himself, 

 that with improved m^ichiuery, methods of manufact- 

 ure, and good variety of caue, a repetition of the 

 f.iilure of sugar-planting in Ceylon would be imposs- 

 ible. As far .as I can remember I have the authority ot 

 your valuable paper for stating that the canes 

 urow must luxuriantly in the Dumbara valley when 

 iirst planted, and the failure was only owing to the 

 imperfect apparatus and method of manufacture of 

 those days, which have since been so far improved 

 that with modern machinery for boiling, etc , and a 

 good variety of cane, the manufacture might be, and 

 in facti.s, rendered easy. 



If sugar can be made at Baddegama--" and 

 very good sugar it is" it can be made elsewhere in 

 Ceylon. 



As I have mentioned above, the canes grew most lux- 

 uriantly formerly in Dumbara, and a very large yield 

 was expected ; but when the juice was put into the 

 boilers it was boiled and boiled and boiled, «ithno result. 

 This on the face of it shows an imperfect method of 

 manufacture, for it is admitted that there was 

 abundance of juice in the caurs, and has since been 

 remedied at Baddegama, which was at first equally 

 a failure. 



Now, ns to the land fit tor sugar cultivation in Cey- 

 lon, much might be said. I myself know of thousands 

 of acres between Badnlla and Kandy, with a fair 

 rainfall, rich soil, and facilities for transport by road 

 and river to Kandy or Trinconialee, level enough to 

 cn.able ploughing, etc., to be carried out, and only 

 awaiting the introduction of capital and energy to 

 become a scene of activity and prosperity, instead of 

 the dense feverish and deserted wilderness it is at 

 present. If capitalists who are now seeking in Borneo, 



