1853] 



REPORT ON TABLE-MOVING. 



2? 5 



miles.) It soeras liiglily probable that lier speed will be increased 

 by alterations and improvements in lier machinery, but it is to 

 be obserx'ed that when depressed to her load line, the full esti- 

 mated power of her engines will propel her at no more rapid rate 

 •than 8^ miles per hour, in still water, and less than 7 miles per 

 hour at sea. 



6. Application to Inland Navigation, <&€. — The weight of 

 the caloric engine, and ihe large amount of .space which it re- 

 quires, would seem to preclude all hope of applying it success- 

 fully, in its present form, to river or lake navigation, or to railroad 

 locomotion. (See table on p. 408.) In its application to manu- 

 facturing pur|joses and to iio drams of mines, &c., the same ob- 

 jections will hava much less foi'ce, anil a favourable result niay 

 therefore be more confidently expected. In this point of \'iew^, 

 Jiowevei-, a compari-son shonl.l be instituted between the caloric 

 engine and the high pressure steam engine, working very e.vpan- 

 sivel}'. 



General Conclusions. — The more important general conclu- 

 sions to which this comparison has conducted are, 



1. That Ei'icsson's Hot Air engine', r.s compared with the 

 condensing marine steam engine in its most economical operation, 

 lias shown the ability to do the same work with the use of from 

 jt to -^ less fuel; and that if its full climated power should here- 

 after be developed, the saving effected woidd bo 70 per cent 



2. That, for the same actual power, its weight is about three 

 times as great as that of the marine stefim engine, and th;it in 

 case its estimated power should be obtained, its weig't would bo 

 as much as 30 per cent greater. 



3. That in respect to the space occupied by the engines and 

 coal, the advantage is decidedly in favor of the steam engine, 



4. That, the groat weight of the engine in proportion to the 

 power developed, must prevent, for the present, the realization of 

 Ti high speed in the propulsion of vessels. At the same time it 

 is to be admitted that the full estimated power is adei|uate to the 

 production of high velocities. Time alone can decide the ques- 

 tion whether or not this maximum power is really obtainable. 



5. The great weight of the engine, and the space occupied by 

 it in its present form, will in all probability pievent its adoption 

 foi- the purposes of inland aavigation and railroad locomotion, in 

 preference to the steam engine. If used as a land engine, these 

 features will be less objectionable; aecordingl}', it is only in this 

 form of application, and in those cas&s of marine navigation in 

 which speed is likelv to be sacrificed to economy of fuel, that the 

 caloric engine may be confidently expected to achieve a decided 

 triumph o\er the condensing steam engine. 



Although this discussion has brought us to the conclusion that 

 the new motor is not likely to equal the extravagant expectations 

 which are so widely entertained with regard to its capabilities, 

 still it must be freely conceded that the invention of a new en- 

 gine, in resjiect to wdiich a just claim to sujieriority over the steam 

 engine can be asserted, in any particular, is a great achievement, 

 and th.at the ingenuity and mechanical skill displayed in the in- 

 vention and construction of the Caloric Engine cannot be too 

 highly extolled. 



Report on Table-Slaving.* 



When a number of persons .sit or stand round a table, their 

 fingers resting slightly upon it, it frequently, though not in\'aria- 

 bly, happens tliat the table begins to move ; as soon as this mo- 

 tion-is perceived, the experimenters follow its course, and turn 

 round and round with more or less velocity; but as soon as the 

 hands are removed from the table it gradually stops. 



*LiOi}don. Mfctical Journal. 



The latter part of the experiment — namely, the rotation of the 

 table — involves a fallacy, for the rapidity of its movement is in 

 no degree owing to any inherent power of motion in itself, but 

 is solely due to the force unconsciously exerted upon it by the 

 exjierimenters, and the velocity of ihe motion is entirely and 

 dire.-tly proportionate to the amount of force expended upon it, 

 in addition to the momentum it has already accpiired in passing 

 from a state of rest to one of motion. The table no more com- 

 pels the persons to follow its movements than the garden-roller 

 drags the gardener who pushes it before him ; in both cases the 

 vis a terijo is the moving force, and the table and the garden- 

 roller do no more than obey the impulse communicated to them. 



It must, howevei-, be admitted, that Ihe first mo\ement of the 

 table i.s not so easily explained, for the results of our own experi- 

 ment*, and those of other persons fully deserving of confidence, 

 have placed the fact beyond a doubt, that this movement of the 

 table is performed without any conscious effort on the part of the 

 ex|ierimenters. It remains, therefore, to be shown by what me- 

 chanism this efi'ect is produced, and we shall have no difficulty 

 in solving the jsroblem by reference to physiological principles 

 which ai-e well-known to the Profession. The fact is, that the 

 movement in question is due to involuntary muscular action at 

 the ends of the fingers, exerted upon the table. The direction 

 of the mo\ement is regulated, not by the will, but by the domi- 

 nant idea in the mind, and the term ideo motor may very proper- 

 ly express the action in question. It is necessary, however, to 

 explain more fully the class of efleets to which the term ideo 

 motor may be applied. 



It is well known, that the movements of the human body may 

 be divided into voluntary and involuntary. The actions of 

 walking, of playing musical instruments, etc., are instances of 

 the first; those of circulation and digestion are examples of the 

 second. But there is also a class of actions comprising the ordi- 

 nary phenomena of inotion, which are certainly not under the 

 control of the loill, but w hich, nevertheless, are directed by the 

 emotions or the idfas. Thus, the somnambulist walks in obedi- 

 ence to some mental impulse, wdiile the will is dormant; and the 

 ])erson wdio dreams, often executes mo\ements in which the will 

 lias no pait, but wdiich are excited by ideas or emotions. Again, 

 although the will has no control over the action of the heart and 

 arteries, yet the ideas and emotions exercise a distinct influence 

 u]ion those organs ; and when attention is directed to their pul- 

 sations in nervous persons, the movements have been accelerated 

 or retarded, or have become intermittent. Now in all these 

 cases, the ideas or the emotions act upon and direct the move- 

 ments without the intervention of the will. In the case of table- 

 turning, the ideas are concentrated upon the expected movement, 

 and the muscular ap]iaratus of the fingers obeys, unconsciously 

 to the experimenter, the dominant impression in the mind. 



When a table is readily moveable upon its feet, or upon cas- 

 tors, a small amount of force, voluntarily applied by the fingers 

 will cause it to revolve. This mobility is still more obvious when 

 the force is distributed uniformly by a number of persons all 

 round the table. 



The amount of muscular force necessarily concerned in ac- 

 complishing the revolution is readily procur.d, independently of 

 will. Let four or five persons place their distiibuted fingers upon 

 some surface, and retain their position for a few minutes, unre- 

 lieved by change; let there be an expectation of some possible 

 result, and there will soon bo perceived a tingling in the skin, 

 along the course of the muscles, and a degree of tension, which, 

 without volition, altogether, e\entuates in reflex, or, as it would 

 be styled in common language, involuntary action. In tabic 

 turning, there need not be any voluntary movement, for mu cu- 

 lar tension, provoked by irritation, sensation, emotion, or fiie<i 



