504 On a Meteoric Stone. Operators in Mathematics. [Feb. 2 r 



II. " On a Meteoric Stone found at Makariwa, near Invercar- 

 gill, New Zealand." By G. H. F. ULRICH, F.G.S., Pro- 

 fessor of Mining and Mineralogy in the University of 

 Dunedin, N.Z. Communicated by Professor J. W. JUDD, 

 F.R.S. Received December 14, 1892. 



(Abstract.) 



The specimen described in this memoir was found in the year 1879 

 in a bed of clay which was cut through in making a railway at In- 

 vercargill, near the southern end of the Middle Island of New 

 Zealand. Originally this meteorite appears to have been about the 

 size of a man's fist, and to have weighed 4 or 5 Ibs., but it was 

 broken up, and only a few small fragments have been preserved. The 

 stone evidently consisted originally of an intimate admixture of 

 metallic matter (nickel iron) and of stony material, but much of the 

 metallic portion has undergone oxidation. Microscopic examination 

 of thin sections shows that the stony portion, which is beautifully 

 chondritic in structure, contains olivine, enstatite, a glass, and prob- 

 ably also magnetite, and through these stony materials the nickel 

 iron and troilite are distributed. The specific gravity of portions of 

 the stone was found to vary between 3'31 and 3*54, owing to the un- 

 equal distribution of the metallic particles. A partial chemical 

 examination of this meteorite was made by the author and Mr. James 

 Allen, but the complete analysis has been undertaken by Mr. L. 

 Fletcher, F.R.-S., of the British Museum. The analysis, which when 

 finished will be communicated to this Society, has gone so far as to 

 show that the percentage mineral composition of the Makariwa 

 meteorite may be expressed approximately by the following numbers : 

 nickel iron 1, oxides of nickel and iron 10, troilite 6, enstatite 39, 

 olivine 44. 



III. "On Operators in Physical Mathematics. Part I." By 

 OLIVER HEAVISIDE, F.R.S. Received December 15, 1892. 



Connexion between a Flux and a Force through an Operator. 



1. In the investigation of physical questions we often have to- 



answer such a question as this : Given a force /, a function of the 



ime, acting at one place in a connected system, find the effect F, of 



5ome given type, produced by the force at its own or some other 



Or it may be that it is not an. impressed force that is given, 



but displacement of some kind. Or, in order to produce mathe- 



