% of the Coast of the United States on the Gulf of Mexico. 17 
my former papers in the form given by Professor Lloyd. It is 
easy to obtain a general view of the movement of the diurnal 
wave in this way, but the selection of the groups required a te- 
, dious set of trials and the discussion of many groups which ap- 
} peared natural, proved very unsatisfactorily. The burthen of the 
a computation for this work has fallen upon Mr. John Downes. 
‘l'able No. 4 shows the groups selected, with a letter attached 
for reference, the names of the stations constituting the groups, 
the mean latitude and longitude, and cotidal hour of the group, 
the values of the coefficients of each, the angle of the cotidal 
line with the meridian, the velocity of movement of the wave, 
and the same in miles per hour. 
TABLE 4. 
N MM? + NI 3 
: fee | 5 
$ 3 3Z ff. of cotidal| Angle | £2 3 ir: 
ES 3 = jhour for one geog. N| 3-328 = 
Stations. So = S — of : tang M + Se poll 
3 3 3 sf 3 |Cotidal| ©ZES| 2 
2 FI Fi & s angle. |: SmS| & 
: |e |e : 3 om [Bese = 
= = = =| 4 ASmS| = 
A Cape Florid fay Key, 0s: o: 0) oe wits 
ae Key Aen Some - 3 /- 1978|- 0509|-14 28] 2-052 | 292 
ndian K 
ott ey Key West, t'g1 gale re 28|- 0'890|- 3240 74 38} 3360 | 178 
Soda te Esmont Key, |'go soley 0124 10| 5-261) 1-6951-17 53] 5518 |109 
| Cedar Keys, | | 
pf 7129 3125 45) 1:095| 2858/-65 5} 2-@00 | 227 
organ, - 86 4930 1 
F Cedar Key, St. Marks, St.) | 
eorge’s, Pensacola, Ft. 
Motgan: Cat. Isl wer gs 7,86 31/29 43.25 56) 0:048| 0-911\-86 58) 0-910 | 660 
West Pass, 
G St.Georges, Pensacola, Ft } ee 
Morgan, Cat IsI'd, South ‘87 4129 49.25 50/-0275| 1-099) 75 59} 1197 | 531 
West Pas ee } 
H South West Pass, Derniére | ole " 
| Asl'd, Caleasien, Galves- 693 4598 2826 3/- 0°241|+0°944) 63 19] 0974 | 61-6 
bid s, Brazos. | | : 
On the character of these are I would remark as follows. 
E\St.G ; 
St, George, Pensacola, Ft. 25 55 0-055! 2645/-88 49] 2-645 | 22-7 
probably real. The computed and observed cotidal hours differ 
at the greatest but one minute and a quarter. The next group 
C, gives a satisfactory idea of the movement of the wave passing 
round the Tortugas and up along the coast of the peninsula, 
over the extensive flat which borders it. The next group D, 
_ Cedar Keys, St. Marks, and St. George’s, presents a —. agree- 
ment between the computed and observed cotidal hours, and a 
direction and velocity agreeing with what might have been sup- 
, a3" 
