Lately our laboratory has been kept in a disagreeable state of vibration by the machinery in the basement. Last night the nuisance seemed wondrously increased for the partitions racked and yawned until I could step through a breach from Dr. H's room into the Comparative Anatomy. Here I found sections of the floor displaced and could look down upon a crude and ponderous pumping engine, which seemed to have wrought the mischief. At this point the L's appeared, both wearing beards of a very light color. I went with them to Lowell and we found ourselves in a street bounded by huge mills built of dark granite like the buildings at the Navy yard. A sign read -- Brig Square. The place was quite deserted although the sun was high and shone warmly. We went along to a residential part of the city and tried the door of a house in a handsome block. It was not locked. We went in and poked around the rooms, which were richly furnished. We explored every floor without meeting anyone. We did not take or injure anything. At last, as we came into the front hall again, we heard heavy foot falls on the stairs. We hurried to the door. Something made me walk unevenly, and looking down I saw I had lost an overshoe. Glancing back, I spied it on the parlor threshold and I promptly kicked my remaining rubber after it, thinking, however, that it might identify me. The steps sounded close behind as we rushed out and ran with all speed down the street. I counseled turning at the second corner and we did so, looking back to see a policeman pass at a headlong rate.