312 U. S. COAST AND GEODETIC SURVEY 
Hy Mean water level above datum used for tabulation. 
h (1) Mean longitude of sun; also rate of change in same. 
(2) Height of tide at any time. 
hg Height of equilibrium tide involving cube of moon’s parallax. A second 
digit in the subscript limits the height to that due to terms of the single 
species indicated by this digit (pars. 97 and 101). 
hg Height of equilibrium tide involving 4th power of moon’s parallax. A sec- 
ond digit in the subscript has the same significance as in the case of hs. 
I Obliquity of lunar orbit with respect to earth’s equator. 
1 Inclination of lunar orbit to the ecliptic. 
1 Tidal constituent. 
] Longitude of moon in its orbit reckoned from lunar intersection. 
i, Kk, Tidal constituents. 
KJ, KP;, KQ; Tidal constituents. 
k Difference between mean and true longitude of moon (par. 59). 
L Longitude of place; positive for west longitude, negative for east longitude. 
L,, LP, Tidal constituents. 
M Mass of moon. 
M;, Ms, Ma, My, Me, Mg Tidal constituents. 
Mf Tidal constituent. 
MK;, 2MK:, MK, Tidal constituents. 
Mm _ Tidal constituent. 
MN, 2MN,, MNS, Tidal constituents. 
MP, Tidal constituent. 
2MS,, MS,, 2MS., 3MS8s, 2(MS)s Tidal constituents. 
MSf Tidal constituent. 
MSN¢, 2MSN;_ Tidal constituents. 
m Ratio of mean motion of sun to that of moon (par. 62). 
N Longitude of moon’s node; also rate of change in same. 
No, 2Ns, NJ; Tidal constituents. 
O,, OO, Tidal constituents. 
2, Mean longitude of lunar perigee reckoned from lunar intersection (par. 122). 
P, Tidal constituent. 
p (1) Mean longitude of lunar perigee; also rate of change in same. 
(2) Numeral indicating species of constituent, frequently written as the 
subscript of the constituent symbol. In special case used with long- 
period constituents to show number of periods in month or year. 
Dp Mean longitude of solar perigee; also rate of change in same. 
Q Term in argument of constituent M, (par. 123). 
Qa Factor in amplitude of constituent M, (par. 122). 
Qu Term in argument of constituent M; (par. 122). 
Q:, 2Q; Tidal constituents. 
R (1) Amphtude of constituent pertaining to a particular time (par. 148). 
(2) Term in argument of constituent L, (par. 129). 
itv Factor in amplitude of constituent L2 (par. 129). 
Ry, RP; Tidal constituents. 
r Distance of any point from center of earth. 
S (1) Mass of sun. 
(2) Longitude of time meridian; positive for west longitude, negative for 
east longitude. 
(3) General symbol for coefficients of sine terms in Fourier series (par. 187). 
(4) Working seale factor of predicting machine. 
S’ Solar factor U,/U (par. 118). 
S1, S:, Ss, Si, Ss, Ss Tidal constituents. 
Sa Tidal constituent. 
Sk 3 Tidal constituent. 
2SM, Tidal constituent. 
