with far greater difficulty of operating aircraft from small British farms, the British Government assumed topdressing aircraft would need to operate from an ordinary runway. Economies of scale then dictated using large aircraft, which would in turn have to fly higher. Accordingly, in 1950 the RAF conducted trials over Scottish farm land with Avro Lincoln and Avro Lancaster bombers carrying canvas trays with 5 tons of superphosphate in and paper bags designed to burst on impact. These trials were a failure due to poor spread achieved from the bags. The Bristol Aeroplane Company conducted private trials on hill country in the same year with scaled-up versions of the New Zealand hoppers fitted to Bristol Freighters. The success of these trials was widely publicised through Farmers' Weekly magazine. Hopper conversions were marketed for the Freighter and the even larger Handley Page Hastings. However low capitalisation for start up costs and the difficulties of low level operation in large transports led British private industry to use smaller machines, even though they could not operate directly from farms. Success in New Zealand Several factors lay behind the development of aerial topdressing in New Zealand. The New Zealand public service gave its employees time and resources to pursue their ideas and publish research. Many farms included hill country, where it was impossible to spread fertiliser by truck. New Zealand farms tended to be large enough to make the costs worthwhile. New Zealand farmers were well educated and enjoyed the third highest standard of living in the world. High prices for lamb, beef, and wool in the early 1950s gave farmers the extra capital. World War II had left behind cheap, war-surplus Tiger Moths and highly trained ex-air force pilots. The majority of the 40,000 plus New Zealanders trained by the RNZAF were aircrew. Most were sent to Europe, and served in squadrons where the ground crew were from the United Kingdom. On returning to their rural homes, many bought cheap war-surplus aircraft, particularly the Tiger Moth primary trainer, available for £100. These were used for weekend flying, but also dropping fencing, feed and people into remote areas, as well as occasional aerial sowing and dropping of rabbit poison. By the end of 1949 there were five firms; Airwork had five Tiger Moths, James Aviation three, Aircraft Services three, Gisborne Aerial topdressing (which was to become Field Air) had one, and Southern Scenic Airtrips had