MIRAGE 109 



Flype 'em, slit 'em, twist 'em, 



Lop-looped laps of paper ; 

 Setting out the system 



By the bones of Neper. 



Clear your coil of kinkings 



Into perfect plaiting, 

 Locking loops and linkings 



I nterpenetrating. 



Why should a man benighted, 



Beduped, befooled, besotted, 

 Call knotful knittings plighted, 



Not knotty but beknotted? 



It's monstrous, horrid, shocking, 



Beyond the power of thinking, 

 Not to know, interlocking 



Is no mere form of linking. 



But little Jacky Homer 



Will teach you what is proper, 

 So pitch him, in his corner, 



Your silver and your copper. 



One of Tait's most beautiful self-contained papers is his paper on 

 Mirage (1881), published in the Transactions of the R. S. E. (Sci. Pap. 

 Vol. i, No. LVIII). It is worked out as an example of Hamilton's general 

 method in optics. Not only is it an elegant piece of mathematics, but it 

 shows to advantage the clearness of Tait's physical intuition in his assumption 

 of a practically possible vertical distribution of temperature and density 

 capable of explaining all the observed phenomena. A less technical account 

 of the paper on Mirage was published in Nature (Vol. xxvm, May 24, 1883) 

 under the title " State of the Atmosphere which produces the forms of Mirage 

 observed by Vince and by Scoresby." This article is printed below. 



In 1886 Tait's attention was strongly drawn to the foundations of the 

 Kinetic Theory of Gases, on which subject he communicated four memoirs 

 to the Transactions of the Royal Society of Edinburgh and a fifth (in abstract) 

 to the Proceedings within the six succeeding years. His first aim, as indicated 

 in the title, was to establish sure and strong the fundamental statistical 

 propositions in the distribution of speeds and energy among a great many 

 small smooth spheres subject only to their mutual collisions ; and the one 

 initial point aimed at was a rigorous proof of Maxwell's theorem of the 

 equal partition of energy. An interesting question carefully considered by 



