SOLAR ECLIPSE, MAY G, 1883. 127 



0".83 — Olio division of lalitiKh^ level = L".7r». Correction tor pivot iii('(in:ility, inappreciable. A 

 glass tliapliragni was used, having ruled ii])oii it 1.'5 lines. The e»iuatorial int(u-vals of the three tallies, 

 determined on the island from the transits of t('u stars of varying declination, are as follows: 



Eqiialoriitl hilcrvals, (JIamp Wtsf. 



.1. 

 B_1 -14.50. 



2 -12.07. 



3 - O.fiG. 

 C— 1 - -1.82. 



2 - 2.43. 



3 - .01. 



4 + 2.44. 



5 + 4.82. 

 D— 1 + 9.G7. 



2 + 12.0G. 



3 + 14.49. 



CnitOXOGKAPII. 



Chronograph ISTo. 8, made by Fautii & Co., of Washington, was used in all time and ]ieii(hi- 

 luni observations, and also in recording the observations of contacts during the eclipse. Two cells 

 of the ordinary crow-foot gravity battery were in the circuit, which included two observing keys, a 

 sounder, Sidereal chronometer (break-circuit), Negus No. 1589 with condenser and the chronograph. 



CHRONOMETERS. 



The two chronometers employed were Xegus 1.589 and Hutton, 202 both Sidereal, and both 

 supjilied with a break-circuit attachment. The former breaks every second, omitting the GOth — 

 the latter breaks every even second and also the 59th. 



PENDULUM. 



The pendulum swung was the Yard Reversible, Peirce No. 3, made at the Coast find Geodetic 

 Survey Office in 1880. It is symmetrical in form with reference to the center of figure, and the ratio 

 of the distance of the center of mass from the point of support for heavy end up and heavy 

 end down is as one to three. It is made of brass with knife edges of steel, and was swung on 

 steel plane. 



A small reading telescope for observing the amplitude of oscillation of the pendulum. 



A mercurial barometer, No. 1936, made by Green, of New York, and aneroid, by Casella, of 

 London. Four thermometers, by Baudin, of Paris. 



OBSERVATIONS FOR TIME AND LATITUDE. 



The pier was finished Sunday afternoon, the 22d of April, but owing to cloudy weather no 

 observations could be made until the evening of the 24th. From that date stars were obtained 

 every evening about 7 o'clock until May 8, inclusive, with the exception of May 3, when wet 

 weather again made it impossible to observe. Good sets were also obtained ~at about 4 o'clock on 

 the mornings of April 2G, 28, 29, 30, May 1, 3, 7 and 8, these morning observations lieing made 

 in connection with the gravity experiments. 



The method of equal zenith distances was employed for latitude, and this work was carried ou 

 at the same time as the pendulum work, thus filling up the time between the evening and 

 morning time-observations. Latitude was thus observed on six nights, but, owing to difficulty 



