38 REPOET— 1882. 



It is sufficient for present purposes to state that the fundamental in- 

 variants (the absolute constant not included) for the systems (2) (2) (4) ; 

 (2) (4) (4) ; (4) (4) (4) ; (2) (3) (4) are respectively 19, 29, 25 and 

 04 in number ; the first, second, and fourth of these totals, viz. 19, 

 29, 64, it will be noticed, are very nearly the same as the numbers of 

 invariants of the systems (1) (2) (4) ; (1) (4) (4) ; (1) (3) (4) which 

 are, as is well known, identical with the numbers 18, 28, 61, of the in- 

 and CO- variants belonging to the quadri-quartic, quarto- quartic, and cnbo- 

 quartic systems respectively. 



It may also be stated that the invariants of the three systems in which 

 only quadrics or qnartics are contained are all unique for a given type ; 

 that is, in each of the three systems there is never more than a single 

 invariant of given degrees in the coefficients of the three constituent 

 quantics resjpectively. 



Report {'provisional) of the Committee, consisting of Mr. Robert 

 H. Scott {Secretary), Mr. J. Norman Lockyer, Professor H. J. S. 

 Smith, Professor Gr. Gr. Stokes, Professor Balfour Stewart, and 

 Mr. Gr. J. Symons, appointed for tlie jpurpose of co-operating 

 with the Meteorological Society of the Mauritius in their pro- 

 posed publication of Daily Synoptic Charts of the Indian Ocean 

 from the year 1861. 



The Committee have no report to submit, for it appears from the latest 

 letters received from Dr. Meldrum that the actual printing ofi" of the pro- 

 posed Synoptic Charts for the Indian Ocean has not yet been com- 

 menced. 



No expense has therefore been incurred as yet, and there has been no 

 occasion to apply for any portion of the grant of 50Z. made at the York 

 meeting. 



However, the Meteorological Society of the Mauritius contemplates 

 the issue of the charts in the course of the coming year, so that the 

 Committee request that they may be re-appointed, and the grant re- 

 newed. 



Report of Committee, consisting of Captain Abney {Secretary), 

 Professor W. G. Adams, Professor Gr. C. Foster, Professor Lord 

 Eayleigh, Mr. Preece, Professor Schuster, Professor Dewar, Pro- 

 fessor Vernon Harcourt, and Professor Ayrton, for the purpose 

 of fixing a Standard of White Light. 



As the experiments conducted by the Committee are still in progress, 

 the Report cannot be ready for presentation this year. 



