Mav 7, 1886.] 



-THE TROPICAL AoRiCVt'PtsMii-V. 



ns 



which do not tiiiniber more than perhaps a hundred 

 species out of the lOO.'OOO with which the botanist hae 

 to deal. But even of most of these during the last 

 generation, as population has increased and the can-ying 

 trade has been completely revolutionised by steam and 

 electricity, the countries in which they are grown have 

 been changed very materiaUy. The total amount of 

 foreign food imported into Great Britain in 1SG4 was 

 an average of 26s. per head. In 1883 it amounted 

 to 69s per head, the difference representing a lump 

 sum of £77,000,000 per annum. In 1864 the total 

 amount of foreign grain and flour imported into the 

 country was worth £20,(00,000 sterling; in 1^83 it 

 cost £70.000.000— au increase of £50,000,000 in twenty 

 years. Before the war of secession iu the Vnited 

 states the Southern States had almost a monopoly of 

 the trade in raw Cotton ; last year the value of the raw 

 Cotton exported from India was between £14,000,000 and 

 £15,00«-M>00 sterling. In 1840 China had a monopoly of 

 the Tea trade. In 1883-4 the value of the Tea esporttd 

 from India was 408 lakhs of rupees, or over £4,000,000 

 sterling. In 1850 the area under cultivation of Tea 

 in India was not more than 1,000 acres, yielding an 

 aunu:il crop of £250,000. In 1880 the area under 

 cultivation was 2U6,700 acres, yielding an annual crop 

 ot 4'\(X)O,0('O lb., representing au invested capital of 

 £15,00(^000 sterling : au annual expenditure of £3,000,000 

 iu wages, and. at tho rate of five to an acre, yielding 

 means of subsistence to over 1,000,000 natives. The 

 animal export of Colfee from Ceylon, instead of being 

 now as it was iu the years between 1S65 and 1878, 

 £5,000,0(Kl sterling a year, has dropped to £1,500,000.— 

 J. G. Bakeh. 



GIBB'S TEA WITHEBER AND JACKSON'S 



AND DAVIDSON'S DIBEKS 



have been thus uuticcd iu the Londou letter of tho 

 Indian Taa Gazette: — 



I tlunk I told you that lately I went out to Rlr. 

 Gibbs' quaint old place Gillwell Park in Essex, to 

 inspect a model of his proposed withering machine. 

 Since then a laudatory notice of some length upon 

 3Jr. Gibbs and his inventions has appeared in the 

 Times, but as very little is said about his drier for tea, 

 and that much is already well known, it is hardly 

 of special interest to your readers. His model is an 

 adaptation of the principle cf his drier, ooly the 

 witherer is to be probably constructed of tanned canvas 

 stretched upon a wooden frame, thus reducing the 

 cobt enormously, as also the weight. It is to work at 

 a much reduced temperature, of course. I saw privet 

 leaves, dripping wet as takeu from a bucket of water 

 thoroughly dried cf nil surface moisture, without the 

 slightest appa.rent injury to the leaves, after having 

 been passed oncf through the cylinder of the model, 

 the initial temperature being about 200^' Fahr. The 

 same leaves were passed through a second time, but 

 at an initial temperature of only about 150,* and on 

 falling out the leaves were to all appearance and touch 

 perfectly withered. The cylinder was revoivedr toy 

 slowly by hand. The hot blast was filtered thgough 

 asbestos, a thickish pad. Of, course, the working tem- 

 perature was much below the initial temperature, as 

 cold-air below 6(f Fahr. was drawn in at the open end 

 of the cylinder from the room, which cool air, of 

 course, mi.xed itself with the hot-air, as soon as the 

 ]attcr left the air-duct. The fan was turned at much 

 ess speed than wheu used for dryivy. So far all 

 promises well, as the machines being cheap, a suffi- 

 cient number could be used, requiring less tlmn a 

 donkey-power each to do the largest quantities of leaf. 

 And I saw iiuitc sufficient to satisfy me that in " in- 

 telligent " liands very little practice would be required 

 to produce, to all appearance and test of touch, per- 

 fectly withered leaf in the most rainy of rainy weather. 

 But ! and there is always a but— it has seemed to 

 me that, in the discussion going on about withering. 

 and in the minds of inventors, too, one point is kept 

 too much out of view. "We all agree that nature has 

 a stage at which the best possible conditions rule for 

 effectiug given chuges, aud that withering coniep 



under this— may I call it, Law. "\Vs can, doubtless, 

 by experiments, find out the best conditions, and bring 

 about those conditions artiJicuiHi;, for so withering tea 

 leaves as to turn them out perfect to all appearance 

 and test of touch. But Ibis is not all that i« neces- 

 sary by any means. The leaves may be of a lovely 

 uninjured appearance and soft as down, but, if this 

 effect has been produced too rapidhj to the detrimeut 

 of certain invisible, intangible, yet important con- 

 ditions, the leaf so withered, will be found very dis- 

 appoiuling when the time for its " fermentation." 

 after the rolling, has come, and gone, and the leaf 

 is fouud to be still " uufermented ! " This drawback 

 I think might be overcome by steaming the leaf after 

 rolling, to add the moisture necessary to "ferment- 

 ation" which may have been unwittingly driven off 

 in exccas; the wcrst of it all is, however, that this 

 vital point, upon which success will hinge, is just the 

 one the inventor cannot detect, or even experiment 

 upon in his covntry, 



Mr. "VV. Jackson has returned for a time, and at 

 dinner two nights ago, on his passing through Towu 

 gave me a most satisfactory account of the success 

 his driers have met with in Ceylon. AVe first met at 

 the installation of bis fir.'it completed rolling-machine 

 in the Sibsagor district, iu 1873, I think it, was, and 

 time seems to have treated him very kindly sinoo 

 then, to judge by his appearance and active gait, the 

 latter full of characteristic energy and "go." His driers 

 have evidently now fulfilled bis anticipations, and ho 

 is fully armed with those latter-day weapons, reliable 

 testimonials, with which to demolish all hesitation on 

 the part of cautious Directors. The machines arc 

 costly, he allows, but — there it is gain — they arc autom- 

 atic and so require the minimum of attendance; 

 they are durable and simple in conbtructiou, and will 

 not entail frequent repairing; the tea is never hanclj- 

 ed or submitted to friction or any motion likely to 

 injure its bloom; and the outturn is considerable, 

 whilst the space occupied is very tritling. 



Mr. Davidson the other day, whilst over on a visit 

 from Belfast, showed me a large model of his new 

 " T-Sirocco," and explained its various advantages over 

 the earlier a " T-Siioccos" first sent out. The amount 

 of etailed experiment personally conducted by him- 

 self to arrive at the present improvements must have 

 entailed months of close application, aud constant 

 labour aud thought. The improvements chiefly related 

 to the construction of the stove which has been eu- 

 largeil and rendered more durable, aud capable of 

 supplying a vastly increased volume of heat ; to the 

 insertion of dampers above the stove to retaiu anti 

 thereby prevent loss of heat, whilst getting up the 

 temperature previous to commencing drymg ; and laht, 

 but by no means least, to the very perfect equali/.- 

 ation of temperature at all points under tho trays. 

 To obtain the latter object, nothing but actual e.x- 

 perimcnt could be relied upon, and hundreds of 

 trials iu arranging the new draught-guides, their 

 shapes and positions, were necessary before the present 

 satisfactory result was obtained. The temperature is 

 now f'O equalized as to show no greater variation tlian 

 50 Fuhr. at any two points. 



Mr. Davidson has good cause to anticipate a vastly 

 increased working-rapacity for these new T-Siroccos, 

 and a mucli longer hie for the stoves. It was found 

 that the excellent ()uality of the fire-l>ricks employed in 

 last year's stoves concentrated the heat too intensely 

 upon the iron portions, getting up the temperature at 

 these latter points to almost smelting heat, by compelling 

 these to receive not only their own share of the heat, 

 but th^t of the surface of firr-brick too, which latter 

 radiated its share of heat, aud bestowed it so to 

 speak upon the respective iron j)ortionR. TIk; fire- 

 bricks have in consequence been done away witli the. 

 temperature thereby being now evenly distributed 

 over the whole interior surface of the stove, sbonld 

 not b(; found too severe, and the stove being increased 

 in size, its heating capacity has been iufreased. 



Mr. Davidson. 1 might mention in parsing, has been 

 lately induced, iu consequence of repeated requests, 

 to start selling tea io pound packets from his "Sirocco 



