110 
The Uniformity of Fine Hard Para. 
In my opinion the sole reason for the uniformity of Fine Hard 
Para is the law of averages. Each ball of Fine Hard Para probably 
takes from one to two months to prepare and thus any daily variation 
of the latex in concentration, etc., or any variation in the temperature 
or other conditions of the smoking process employed, are averaged. 
This indicates at once a method for rendering plantation rubber 
more uniform in bulk, viz., the mixing together in each case, of 
rubber prepared on different dates. 
Having summarized the causes of variability in plantation Para 
rubber and shown the principal factors which have an influence on 
the problem and stated the probable reason for the uniformity of 
Fine Hard Para, it can easily be seen what remedies should be 
adopted to secure uniform results. It is obvious that the problem is 
not excessively difficult on any one estate for one type of rubber, but 
that considerable difficulties arise in the endeavour to make all 
estates carry out a similar practice. 
In considering the problem of variability we must at once 
realize that uniformity can only strictly apply to one type of rubber. 
Thus thin pale crepe is intrinsically distinct from smoked or plain 
sheet and as long as there is a market demand for this grade, which 
will probably be always, since this type of rubber has created its 
own market for specific purposes for which no rubber of darker 
colour could be employed, it is impossible for estates to make one 
uniform product, since thin pale crepe, from its mode of preparation 
will almost certainly always have a different rate of cure to smoked 
sheet. It might be suggested that this type of rubber be made as 
the sole first grade. The- answer to this is that thin pale crepe is 
almost always inferior to smoked or plain sheet in tensile properties 
and hence should not be used for articles in which strength rather 
than colour is a desideratum. 
It is thus evident that for present demands we must prepare at 
least three and probably four grades of plantation rubber, that is 
either two first grade and one second grade or two first grade and two 
second grades. The probability is that four grades is the minimum, 
since it does not seem desirable from our researches to combine all 
lower grades. The best solution is probably the preparation of pale 
crepe and one other first grade and the preparation of two lower 
grades as follows : No. 1 lower grade crepe to consist of lump, 
skimmings and picked scrap, and No, 2 lower grade crepe of bark 
shavings plus earth scrap. 
It is not proposed here, however, to deal with lower grades but 
with first grades only, although in one respect, the question of 
“ lump ” rubber or cup and bucket coagulations, is of interest, as 
will be seen later. 
