the trick specialties began to crop out during the first summer. Tipsy, always the lithest and quickest, became expert in jumping and catching on the fly. Bum, all of his own accord, took to sitting up and "begging." Little Topsy would sit up and "speak." Nig did not develop any specialty, and never really discovered his mission in life until he was taught to "fetch." As to the learning itself. Bum and Tipsy were about as quick and much more docile than Topsy and Nig.
It was stated above that during the second month after administration of alcohol spontaneous activity of both Tipsy and Bum became noticeably impaired. This gradually and steadily increased until, last spring, it seemed to me from daily observation that the alcoholics were not much more than half as active as the normals. How to secure an objective expression of this fact presented some difficulties at first. To put them in large recording cages, such as we use in the laboratory to study the daily activity of rats and mice, would clearly be an imposition on a dog's good nature, and would possibly suppress his activity in proportion to his intelligence. To watch four dogs during the twenty-four hours would require four observers, and their presence would be a disturbing factor.
Pedometers were thought of, but none could be found suitably constructed for use with the dogs. Finally, Waterbury watches were obtained and, by removing the hair springs, weighting the balance wheels unequally, and by proper adjustment of buffing pins so that the balance wheel could move just far enough to release the escapement, a watch resulted which ran only when shaken. After a month of preliminary trials an adjustment was attained so delicate that the watch could hardly be jarred so slightly as not to release the escapement one tooth, and the two could be shaken, violently or gently, and in any position for an hour at a time (fastened firmly together) without showing a variation of more than two seconds on reading the hands.[1]
The watches are now placed in stout leather pockets in specially constructed collars and the dogs allowed to wear them. The results are graphically expressed in Fig. 17. The watches were read every evening at exactly six o'clock, and the reading plotted so that the angles in the lines for each dog correspond to the number of minutes the dog has ticked his watch during the twenty-four hours. The chart explains itself. Bum is seen to develop seventy-one per cent of Nig's activity, and Tipsy only fifty-seven per cent of Topsy's.
The watches, of course, give us only the total quantity of
- ↑ For valuable assistance in accomplishing this adjustment I wish to express my thans to Mr. Albert P. Willis, Fellow in Physics, Clark University.
