operation. By the end of 1924 the stock of war surplus commercial vehicles ceased to be a factor and the group's export sales were at an all-time record. The following year group profits trebled and the Guildford extensions paused in 1920 were resumed but the chairman made no other comment than confirming the wisdom of Dennis Brothers' purchase of White and Poppe. The extraordinary prosperity of Dennis Brothers' core business was demonstrated the next year when instead of issuing yet more bonus shares to shareholders they repaid £250,000 capital to their shareholders because the company held too much cash (£467,000 at balance date) for its own requirements. The White and Poppe operation was self-financing and managed to keep pace with the expansion at Guildford. A new engine was brought to market during 1926 and proved "an unqualified success . . . with large numbers of satisfied users". During the 1920s the rapid increase in turnover and profits was not due to increased prices but to higher sales volume. However White and Poppe's large factory was not yet at full capacity. Their principal product remained internal combustion engines. Patented pivoted rocker gear During 1929 new 6-cylinder engines were introduced. Experience had suggested operators would prefer the cheaper to buy and to maintain 4-cylinder engines. The new 6-cylinder engines were bending to the current fashion. A very valuable invention was patented which allowed the lifting of cylinder heads, decarbonising and valve grinding without dismantling the overhead camshaft. At the Annual General Meeting the chairman reported he had been asked to comment on the use of the crude oil engine and the chairman could "only assure him that we are fully alive to the possibilities". Depression A year later the chairman reported domestic sales remained constant but export sales had fallen considerably. A new six-cylinder Diesel engine had been designed and would shortly go under test. It would not be marketed until its performance equalled a petrol engine and to his knowledge no diesel engine did that at that time. Peter's son Erling Poppe (1898-1970) was now works manager at White and Poppe, Alfred White remained managing director. By the end of 1931 "a number" of crude oil (Diesel) engines were out on test fitted to heavy goods vehicles. The following year group profits fell by 41 per cent though substantial reserves allowed the dividend to be maintained. The chairman announced that in