to Hammersmith in 1906. Road traffic also offered a greater challenge as motor buses began replacing the horse drawn variety in greater numbers. In an attempt to maintain income, the company increased the flat fare for longer journeys to three pence in July 1907 and reduced the fare for shorter journeys to one penny in March 1909. Multiple booklets of tickets, which had previously been sold at face value, were offered at discounts, and season tickets were introduced from July 1911. The CLR looked to economise through the use of technological developments. The introduction in 1909 of dead-man's handles to the driver controls and "trip cocks" devices on signals and trains meant that the assistant driver was no longer required as a safety measure. Signalling automation allowed the closure of many of the line's 16 signal boxes and a reduction in signalling staff. From 1911, the CLR operated a parcel service, making modifications to the driving cars of four trains to provide a compartment in which parcels could be sorted. These were collected at each station and distributed to their destinations by a team of tricycle riding delivery boys. The service made a small profit, but ended in 1917 because of wartime labour shortages. The problem of declining revenues was not limited to the CLR; all of London's tube lines and the sub-surface DR and MR were affected by competition to some degree. The reduced income from the lower passenger numbers made it difficult for the companies to pay back borrowed capital, or to pay dividends to shareholders. The CLR's dividend payments fell to 3 per cent from 1905, but those of the UERL's lines were as low as 0.75 per cent. From 1907, the CLR, the UERL, the C&SLR, and the Great Northern & City Railway companies began to introduce fare agreements. From 1908, they began to present themselves through common branding as the Underground. In November 1912, after secret take-over talks, the UERL announced that it was purchasing the CLR, swapping one of its own shares for each of the CLR's. The take-over took effect on 1913, although the CLR company remained legally separate from the UERL's other tube lines. Improvements and integration, 1920–1933 Following the takeover, the UERL took steps to integrate the CLR's operations with its own. The CLR's power station was closed in March 1928 with power instead being supplied from the UERL's Lots Road