There is no provision of the Constitution which requires a senator to be a resident of a particular part of the state, but in some states there is a custom that the two senators shall be taken from different sections. Thus in Vermont custom requires that one senator shall come from the section of the state east of the Green Mountains and the other from the west side. Sometimes when there is a large city in the state it is the custom to choose one of the senators from the city and the other from the country. For a long time Maryland did not trust this matter to custom but by law enacted that one of the senators should be an inhabitant of the eastern shore and the other of the western shore. =Character of the Senate.=--In the early days when the states were generally regarded as sovereign communities, senators were looked upon somewhat as ambassadors to the national government, and the right to instruct them as to how they should vote on important questions was sometimes claimed and asserted by the legislatures. Sometimes the senators obeyed the instructions, sometimes they refused; and in the latter case there were no means of enforcing obedience. Not infrequently senators are "requested" by the legislature of the state which they represent to vote for or against a particular bill. The Senate undoubtedly possesses elements of strength and efficiency which are not to be found in the lower house. As it is a much smaller body, debate there can be carried on with more effectiveness, and the individual member has greater opportunity to make his influence felt upon legislation. The efficiency of the Senate is further increased by the fact that its members are generally men of more mature age and larger legislative experience, many of them having already served their apprenticeship in the lower house. Moreover, owing to the longer term, they are more independent of the popular opinion of the moment and, therefore, under less temptation to yield to popular clamor and vote for measures which their better judgment condemns. These facts, it may be added, have tended to increase the attractiveness of the Senate as a legislative body and to draw into it statesmen of larger ability than the lower house has been able to attract.