thus he stood by the lamp-post surveying the passers-by with undisguised curiosity , and with that gravity known only to the systematic diner , had just enunciated in his mind the formula : `` london has been called the city of encounters ; it is more than that , it is the city of resurrections , '' when these reflections were suddenly interrupted by a piteous whine at his elbow , and a deplorable appeal for alms .