APPENDIX II. 497 



the committee, but his antiquated tactics were quite out-manoeuvred by those of 

 Helix and One-to-One. I need only mention two more names. Mr Commonsense 

 was, of course, present as an ex-officio member, and valuable service was rendered 

 even by Mr Querulous, who objected at first to serve on the committee at all. 

 He said that the inquiry was all nonsense, because everybody knew as much as 

 they wished to know about the dynamics of a rigid body. The subject was as old 

 as the hills, and had all been settled long ago. He was persuaded, however, to 

 look in occasionally. It will appear that a remarkable result of the labours of the 

 committee was the conversion of Mr Querulous himself. 



The committee assembled in the presence of the rigid body to commence their 

 memorable labours. There was the body at rest, a huge amorphous mass, with no 

 regularity in its shape no uniformity in its texture. But what chiefly alarmed 

 the committee was the bewildering nature of the constraints by which the move 

 ments of the body were hampered. They had been accustomed to nice mechanical 

 problems, in which a smooth body lay on a smooth table, or a wheel rotated on an 

 axle, or a body rotated around a point. In all these cases the constraints were of a 

 simple character, and the possible movements of the body were obvious. But the 

 constraints in the present case were of puzzling complexity. There were cords and 

 links, moving axes, surfaces with which the body lay in contact, and many other 

 geometrical constraints. Experience of ordinary problems in mechanics would be 

 of little avail. In fact, the chairman truly appreciated the situation when he 

 said, that the constraints were of a perfectly general type. 



In the dismay with which this announcement was received Mr Commonsense 

 advanced to the body and tried whether it could move at all. Yes, it was obvious 

 that in some ways the body could be moved. Then said Commonsense, Ought 

 we not first to study carefully the nature of the freedom which the body possesses ? 

 Ought we not to make an inventory of every distinct movement of which the 

 body is capable? Until this has been obtained I do not see how we can make any 

 progress in the dynamical part of our business. 



Mr Querulous ridiculed this proposal. How could you, he said, make any 

 geometrical theory of the mobility of a body without knowing all about the 

 constraints 1 And yet you are attempting to do so with perfectly general con 

 straints of which you know nothing. It must be all waste of time, for though I 

 have read many books on mechanics, I never saw anything like it. 



Here the gentle voice of Mr Anharmonic was heard. Let us try, let us 

 simply experiment on the mobility of the body, and let us faithfully record what 

 we find. In justification of this advice Mr Anharmonic made a remark which 

 was new to most members of the committee : he asserted that, though the con 

 straints may be of endless variety and complexity, there can be only a very limited 

 variety in the types of possible mobility. 



It was therefore resolved to make a series of experiments with the simple 

 object of seeing how the body could be moved. Mr Cartesian, having a repu 

 tation for such work, was requested to undertake the inquiry and to report to the 

 committee. Cartesian commenced operations in accordance with the well-known 

 traditions of his craft. He erected a cumbrous apparatus which he called his three 

 B. 32 



