July i, 1889.] THP" TROPICAL 
AGRICULTURIST. 
To the Editor. 
BLACK WATTLE — A CA CIA DECUBBENS, 
VARIETY, MOLLISSIMA. 
Dear Sir, — I find Haldane's and Spon's figures for 
black wattle so different from the results derived 
by you from Mr. Tringham's experiment, that their 
figures may be of interest as suggesting where further 
information is required upon the cultivation of 
black wattle if undertaken on an extensive scale. 
Haldane, in his "Sub-tropical Cultivations," recom- 
mends that the black wattle should be planted 
6x6 ft. apart, or 1,210 trees to the acre ; and he 
says the bark should be harvested in from 5 to 
10 years : the older the trees, the more valuable 
being the bark. The proceeds of an acre he estim- 
ates as follows : — 
From J of an acre in 5th year 2J tons @ £5 a 
ton, less for stripping £1 a ton, baling 10s, carriage 
£1 and cutting 10s ... ... ... £5 0 0 
From j acre in 6 years, 3J tons less as above £3 a ton 7 0 0 
From | acre iu 8th year, 4 J tons less as above ... 9 0 0 
£21 0 0 
Prom whioh deducting original price of land in 
Australia and New Zealand and planting and 
cultivating expenses £6, we have £15 an acre as 
the net profit in 8 years + the fenced land and 
value of timber. Mr. Haldane admits that his is 
a low estimate, the usual estimated net profit being 
£25 an acre at the end of the 8 years. 
Spon's Encyclopedia gives in some respect 
a more detailed estimate of expenditure and receipts 
for a plantation of 100 aores planted 10 ft, apart 
or about 400 trees to the acre: — 
Rent of 100 acres, 8 years @ 6s per acre per 
annum ... ... ... ... £240 0 0 
Ploughing 100 acres a drill 10 ft. apart ... 25 0 0 
Sowing and actual cultivation and seed ... 37 10 0 
Supervision for 8 years & £10 per annum ... 80 0 0 
Pruning ... ... ... ... 50 0 0 
Incidentals ... ... ... ... 27 10 0 
Interest on whole amount expended during 8 years... 240 0 0 
Shipping 15s per ton, cutting 10s ... ... 1,515 0 0 
2,215 0 0 
Yield 6 years J of 400 trees % 56 lb. bark 332 tons. 
„ 7 „ „ say 68 „ „ 400 „ 
„ 8 „ „ say 80 „ „ 480 „ 
1,212® £4 4,85 2 0 0 
Profit on 100 acres in 8 years. ..£2,637 0 o 
The values given by both Haldane and Spon 
appear to be average net values after deducting 
freight, shipping, and London charges, for Spon 
states London values to be £5 to £0 10a for long 
bark and £5 to £12 chopped. 
The age at which the trees come to maturity for 
stripping is you will notice in both the above 
estimates given at 5 to 8 years as against 3J of Mr. 
Tringham's experiment; and the number of trees 
to the aero instead of being 2,720 trees is in one 
estimate 1,210 trees, with similar yield par tree to 
Mr. Tringham's 3i year old, and in the other only 
400 trees, yielding, however, nearly treble the amount 
per tree. Does the extent of Mr. Tringham's ex- 
periment show that the trees may be planted as 
close as 4 ft. apart on a large acreage. I fear even 
6 ft. ap art will be found too close when a planta- 
tion is covered at such distances. 
Spon says the wattle bark is obtainable in vast 
abundance. But the export from Australia 
and Tasmania have fallen from 18,000 tons in 
1876 to 9,500 in 1880. Would this not show that 
the demand for wattle bark is limited? In any 
case oversupply is sure to reduoe the London 
value to be a £5 per ton, and it would be prudent 
to take this as gross value from whioh will have 
9 
to be deducted freight and London charges. Myro- 
bal-ins have dropped from £5 14s per cwt. in 1880 to 
£5 83 6d in 1889. 
Black wattle wood is said to be valuable for cask- 
staves, wheel-spokes, and fence-rails ; but it; is 
evident the trees will require to be well matured before 
the timber can be utilized for any other purpose 
than firewood. Black wattle should make an ex- 
cellent and valuable fence, planted 4 ft. apart in 
drill rows, and this may be the most prudent limit 
of cultivation. Will it grow in the lowcountry ? — 
Yours, J. D. V. 
WINDMILLS WORKED TO DRIVE A COFFEE 
PULPER IN OLDEN DAYS IN UVA. 
Uva, 30th May 1889. 
Dkar Sir, — Just a line to say regarding wind- 
mills. I erected two, both perfectly successful, when 
there was wind and simple and easy to construct. 
One was on the horizontal principle ; the other 
vertical, neither required to be turned to the 
wind, but worked with the wind in any direction. 
I used them to work hand pulpers, shipping the 
pulper handles when there was no wind or 
insufficient. Either could have worked a pump 
easily, so as to fill a reservoir or raise water 
for any purpose. — Yours very truly, 
OLD OUVAH. 
"ACACIA DECUBBENS" FOR TANNING BARK. 
Elephant Nook, 30th May 1889. 
Dear Sir, — With reference to your footnote to 
my laBt letter, I restricted the calculation to ex- 
penses inourred after the delivery of the bark at 
the upcountry railway station ; and (if I am correct 
in estimating the costs of transport, home and local 
charges &c. to be the same on A. decurrens bark 
that they are on cinchona bark) showed con- 
clusively I think that the proceeds of a ton of such 
bark as I despatched would cover the expenses re- 
ferred to, but leave no appreciable margin to set 
against cultivation and charges previous to the 
delivery at railway station. 
In reply to your question as to the quantity 
sent for valuation: the parcel weighed 44 lb. and 
was taken from two trees, — -one large and one small — 
felled for the purpose. It included portions of the 
bark of all parts of the tree excepting small bran- 
ches, and it is most important that this should 
not be overlooked, for the Secretary to the Colombo 
Commercial Co., Ld., London, wrote : " The old 
bark should be shipped and. not the new." 
What the result of the analysis and valuation 
would have been had the sample been of old bark 
only is unknown ; the analysis 34-35 per cent of 
tannin, and valuation £10 to £11 per ton, and the 
yield of \ cwt. per tree were for the mixed bark, 
old and new. 
On the other hand, after looking through the 
T. A., I find 40 per cent of tannin the maximum 
given for bark of Acacia decurrens ; and 'the most 
valuable bark (Acacia pyenantha) is quoted as 
giving up to 47 per cent. But while A. decurrens 
gives up to 500 lb. of bark per tree, the maximum 
for A. pyenantha is given at 70 lb. only. (See T. A., 
1884-5, page 165.) 
I measured a tree (A. decurrens) standing on the 
Military Reserve here the other day, and found it 
at 2 feet from the ground over 6 feet in girth : the 
height of the tree is between 50 and 60 feet, with 
wide-spreading branches 20 feet in length. But 
I have never yet seen a tree of this variety 
without shoots to the root, and understood that it 
was from its habit of spreading from the roots that 
it derived its name. I feel certain that the tree 
your Maskeliya correspondent refers to ia not 
