40 J. WaterhousG — An Account of the Tidal [Xo. 1, 



The several fictitious stars whose tides have been analyzed in these 



investigations, are — 



S, with argument w = y — t) = 15°' 



M „ 7 — o- = 14-4920521 



K „ 7 = 150410GS6 



O „ 7 — 2cr = 13-9-130356 



P „ 7 — 2>7 = M 9589314 



J „ 7 + 0- — w =15-5854433 



Q „ 7 — 30- + OJ = 13-398GG09 



/w, „ 7 — 20- + 7; =13-9841012 



N „ 7 — |o-+ 1 w = 14-2198648 



L „ 7 — io- — i w = 14-7642394 



^ » 7 — fo-— .}« + r; =14-2562915 



A „ 7 — io- + iw — t; =14-7278127 



MS „ 7 ~ icr — ivy = 14-7460261 



and SM „ 7 + cr — 2r; =15-5079479 



The q^imsl.\^o\yx: angles o£ the several fictitious stars, other than S, at 

 mean noon of the day of starting, were found by ^mtting 

 7 = the Sidereal time, 

 y^ = the Sun's mean longitude = 7, 

 o- = the Moon's mean longitude, 

 o- — (o = the Moon's mean anomaly, 



and taking the corresponding numerical values of each element, for the 

 hour and station, from the Nautical Almanac and Hansen's Lunar Tables, 

 and then substituting these values in the preceding symbolic expressions 

 for the hourly variations of the several stars. 



The number of stars and the angular velocity of each star having thus 

 been decided on, a priori, from theoretical considerations, the values of the 

 constants R and € for the tidal constituents of each star have to be deter- 

 mined from the evidence afforded by the tabulated values of the height of 

 the sea-level for every hour of the day during the entire jDcriod of observa- 

 tion ; this should not be less than 371 days. The values of the constants 

 have been computed for the several tides at the three stations of Okha, 

 Nawanar, and Hanstal, and are given below. It will be remembered that 

 Okha is situated at the entrance to the Gulf of Cutch, Nawanar midway 

 up the Gulf, and Hanstal at its upper extremity ; also that continuous 

 observations over a period of not less than 14 months were obtained at the 

 upper and lower stations, whereas at the middle station, Nawanar, there 

 was a break of several months, in consequence of an alteration of the fore- 

 shore during the monsoon of 1874 ; thus the results for Nawanar are far 

 from being as exact and complete as those for the two other stations. 



