All these factors were later taken into consideration in an experiment undertaken on behalf of the Rubber Growers' Association. In this instance unique facilities were provided by the London Asiatic Rubber Company on their property at Semenyih Estate, and it is only fitting that the company should receive the recognition which its enterprise deserves. It would have been a great advantage to have included in that experiment other features which have since come into prominence, but the original scope of the experiment had to be confined to the point of comparing yields obtained in making comparative tests based on one system of tapping with different frequencies. Such data were required as a check upon a Ceylon tapping experiment which had attracted much attention. In that experiment trees were tapped at intervals ranging from one day to seven days; and it was concluded that after a period of three and a half years trees tapped with greater intervals gave yields equalling or exceeding those obtained from trees tapped with shorter intervals. [Illustration: THE SINGLE CUT ON A QUARTER CIRCUMFERENCE, ON AN OLD TREE AND ON RENEWED BARK.] In the Semenyih experiment the system chosen was that which had the greatest contemporary vogue--viz., two superimposed cuts on a quarter of the tree. The various blocks were tapped respectively every day, every second day, and every third day. It was found that the conclusions drawn from the Ceylon experiment were not confirmed. After a period of three and a half years' continuous tapping neither the alternate-day system nor the third-day system gave results in any way approximating to the yield of the daily system. The actual average yields from these systems over the whole period were in the order of-- _Daily._ _Two Days._ _Three Days._ 100 per cent. 60 per cent. 45 per cent.; and throughout the course of the experiment neither of the other sections showed any appreciable improvement in position relative to the daily section. In actual yields "per tapping" over the whole period the alternate-day and the third-day divisions showed advantages of 20 and 35 per cent. respectively over the daily portion. At the beginning of the second year of experiment another section of blocks was opened with a single cut on a quarter, tapped daily. This enabled direct comparison between the values of one cut and two cuts on a quarter in daily tappings and between a daily single cut and two cuts tapped alternate daily. It appeared that the daily single cut yielded over the period of experiment 80 per cent. of that obtained by tapping two cuts daily; and that in the comparison between two cuts tapped alternate-daily and a single cut tapped daily the latter had an advantage of about 40 per cent. in yield.