54 REPORT — 1861. 



accountable diversity which exists in the use of them ; and the result will 

 show, in a most striking manner, the great accuracj' with which experience 

 enables ordinary officials to regulate their system of punishment to the full 

 powers of endurance of the prisoners. 



It is customary at Coldbath-fields for the prisoners to work and rest 

 during fifteen minutes alternately; but at the New Bailey they are placed 

 upon the wheel during twelve minutes, and have only four minutes' rest 

 before the labour is renewed. Hence, the actual period of labour at Cold- 

 bath-fields is only 3| hours, but at the New Bailey it is six hours daily ; and 

 although the labour is lighter at the New Bailey than at Coldbath-fields the 

 total effect per day is the same in both prisons, as tl^e following estimate 



proves : — 



Coldbath-fields. 



Total daily. 



Cubic Inches. 



3| hours' work with 2500 cubic inches of air inspired per minute 562,500 



3f „ rest with 1000 „ „ „ 225,000 



787,500 



New Bailey. 



6 hours' work with 1850 cubic inches of air inspired per minute. . 666,000 

 2 „ rest with 950 „ „ „ 114,0 00 



780,000 



Thus, with the use of instruments differing so greatly in power over the 

 human system, the plan pursued in each gaol is so well adapted to the 

 usual powers of the body, that the difference in the effect is only equal to 

 about three minutes' actual labour upon the treadwheel at Coldbath-fields, 

 and four minutes' at that at the New Bailey. This result illustrates also the 

 accuracy of the method of inquiry thus adopted. 



The influence of this kind of labour over the production of carbonic acid 

 as well as over the rate of the functions, was established by another set of 

 experiments made in a similar manner at Coldbath-fields prison. 



The apparatus employed was that already mentioned, and was used without 

 inconvenience when placed upon a shelf over the wheel and at a suitable 

 distance from the person to be experimented upon. As tliere was neces- 

 sarily some adverse weight placed upon the expiration by the collection of 

 the carbonic acid, it Mas not thought advisable to measure the air inspired 

 also, lest the result should be vitiated by placing some impediment upon both 

 acts of respiration at a time when the deepest and most frequent inspirations 

 Mere demanded ; and hence that part of the inquiry M'as abandoned. The 

 ascent of the body upon the M'heel M-as 28*65 feet per minute, and the M'eight 

 to be lifted was 200 lbs., and hence the labour actually performed Mas 

 equal to lifting 575*558 tons through 1 foot per day. The duration of the 

 labour M'as a quarter of an hour at a time, and the carbonic acid M'as col- 

 lected during three minutes after having been upon the wheel five minutes, 

 and during two minutes after ten or after thirteen minutes. Thus the car- 

 bonic acid was collected during five of each fifteen minutes. The quantity 

 obtained per minute was between five and six times that expired in normal 

 rest, viz., 43*36 grains, 42*9 grains, and 48*66 grains on different days, the 

 latter quantity having been found soon after a good prison-dinner of soup. 

 The average excretion of carbonic acid under the influence of treadwheel- 

 labour was thus 45 grains per minute. 



The rate of respiration was 22, 21, and 20, aud that of pulsation 150 per 

 minute on each of the occasions referred to. 



