The suggestion of a correspondent in yesterday's CRIMSON that the Post Office should be kept open till half-past nine o'clock in the evening instead of closing at eight as at present is an excellent one. It is strange that the needs of so large a postal district as that of Old Cambridge have not brought about this change before. The present hour for closing, we understand, was fixed when the mail for the west left at eight o'clock. Now, however, the mail does not leave Cambridge until half-past nine and as the clerks are now in the office beyond that time there seems to be no good reason why the office should not be open. On inquiry we find that the change of the closing time would not lengthen the hours of the clerks nor be of any appreciable inconvenience to them. In fact there appears to be no objection to the plan from any source. It seems, therefore, that the convenience of a number of the patrons of the office and the occasional advantage to nearly every one, which would result from the longer office-hours, should bring about the proposed change.