Yarrow and Company, Poplar, conducted tests on Holden's system of oil firing on board the first-class torpedo boat Ophir built for the Dutch Government. A trial was first made with coal firing only, and a speed of 24.5 knots was achieved. With oil and coal firing a speed of 26.5 knots was achieved. The great advantage of oil firing, either alone or in combination with coal was that variations in evaporation could be achieved more easily than coal firing alone.