198 Miscellanies. 



the slightest approach to any feeling that would lead me to suppose that 

 four or five times the velocity would disable the engineer from directing 

 and managing the train. Such was the result of my own observations, 

 and it was fully borne out by the experience of the men. I may cite two 

 instances of common occurrence. When the train arrives at the foot of 

 of one of the inclines, the banking engine follows to assist it up. Now 

 one would be apt to imagine, that for the purpose of attaching the new 

 engine, the train would stop, or that if it did not, there would be a con- 

 cussion when the banking engine comes in contact. So completely how- 

 ever are these powerful engines under the control of their directors, and 

 so well are they managed, that a passenger in the train who is not aware 

 of what is going on from ocular perception, is altogether unconscious of 

 any change. I frequently watched this operation, but on no occasion 

 could T perceive the slightest shock, even when situated only one or two 

 carriages from the end of the train. 



" On one occasion the banking engine had got before us on the incline ; 

 as the hooking of it on in such a situation was a much severer test of the 

 skill with which matters are managed, I attended closely to the operation ; 

 we were going fully twenty five miles an hour. . The banking engine 

 gradually slackened its rate and allowed the train to gain upon it, until 

 it could be hooked on, — that done, more steam was given and we pro- 

 ceeded with its assistance, yet not the slightest shock was felt in the train. 

 These facts are sufficient to show, that much greater rapidity is practica- 

 ble so far as the power of managing the apparatus is concerned. As to 

 velocity itself, I made some observations. Twenty five miles an hour is 

 not so very rapid ; over and again I saw bees not merely keep pace with 

 us but fly round and across the coach, and that not by help of any current 

 of air which might be supposed generated, but at several feet distance from 

 the train. At times two specimens of the Libellida grandis kept up with 

 us over half a mile ; while the smaller birds, such as the linnet, were una- 

 ble to cope with the steam. One I almost caught, which while flying 

 with all its might, remained opposite to the window for a few seconds. If 

 a rail road be regarded only as a means of communication between two 

 distant towns, I should have no hesitation in saying that a rate even of 

 one hundred miles per hour could be maintained with perfect safety to 

 the passengers ; but it is different if passengers have to be let out at sta- 

 tions along the line, for then the trouble and expense of stopping the trains 

 comes to be considered. An average of about three minutes is consumed 

 by each stop, including the slackening and regaining of speed before and 

 after stops." 



26. On the Gases contained in the Blood, and on Respiration; by 

 M. G. Magnus. — M. Magnus remarks that it remains a question whether 

 carbonic acid is formed in the lungs by the oxidizement of a part of the 



