The tunnel carries vehicular and passenger traffic under the Thames between Poplar and Greenwich, five miles below the nearest bridge, that at the Tower. Before it was made the two million Londoners living east of the bridges were without any public means of crossing the river. To build an ordinary bridge was impossible with so many ships passing night and day to and from the London Pool. It was decided to take the traffic under the Thames by descending roadways leading to a tunnel some seventy feet below high-water mark. From the time he joined the Council to that day in May, 1897, when the King as Prince of Wales went down to Poplar to open the tunnel, on behalf of Queen Victoria, Crooks was among the keenest of the public men engaged in carrying that great engineering feat through. He made himself so thoroughly master of the details that he was in great demand all over London as a lecturer on the tunnel. The chief engineers on the works who heard the lecture congratulated him on the way he made intelligible and interesting the complicated system by which the tunnel was bored through the clay within a foot or two of the river bed. So satisfied were his fellow County Councillors with the practical work he did at Blackwall that on its completion they elected him Chairman of the Bridges Committee. In that capacity he steered through the Council and through a Committee of the House of Commons two other schemes for tunnels under the Thames, one for foot passengers only between Greenwich and the Isle of Dogs, and the other for general traffic between Shadwell and Rotherhithe, designed on a larger scale than the tunnel at Blackwall. Interest in these schemes, however, can never be so great as it was in the Blackwall experiment, the first of its kind attempted. In the special Blackwall Tunnel number issued by the _Municipal Journal_, Crooks figures among those described as "the men who made the tunnel." Following sketches and portraits of Sir Alexander Binnie (then the L.C.C. engineer, who designed the tunnel), of Sir Weetman Pearson, M.P. (the contractor who executed the work), of Sir William Bull, M.P. (who was then chairman of the Bridges Committee), is a reference to other members of the Committee who took a prominent part in the work. The first place after the chairman is given to Crooks. The _Municipal Journal_ says:-- Mr. Will Crooks, more than any other man, has made Londoners acquainted with the tunnel. His popular lecture on Blackwall Tunnel has been given in all parts of London to all kinds of audiences, and everywhere the clear, picturesque description Mr. Crooks has given, aided by the lantern and his own genial wit, has made intelligible to Londoners, old, young, rich, and poor, what is, after all, a somewhat dry and difficult subject.