THE HOWGATE EXPEDITION TO LADY FRANKLIN BAY. 691 
‘without exception, be kept on Greenwich mean time; that is to say, in the cor- 
rected chronometer time. 
It will thus happen that the simultaneous S. A.'M. observations will be made 
as follows: 7.0om.os. A. M., Washington time; 12 4. 8 m. 12.09 s. P. M., 
Greenwich time; 12 4. 47 m. 58.33 s. P. M., Gottingen time. The only appa- 
ratus recommended as outfit for parties is as follows: 
I.—For TRAVELING PARTIES; FOR EACH Party: 1. Pistar & Martin’s 
Prismatic Circle, which is considered preferable to the sextant, as it measures 
larger angles, which are oftentimes imperatively needed. The instruments should 
be constructed with special reference to use at very low temperatures. 
2. Mercurial, or Artificial Horizon. 3. Two Pocket Chronometers for 
central station. 
ist. The Cassella Astronomical Theodolite, as made by Fauth, as before 
enumerated under the head of ‘‘ Magnetic Work.” If this cannot be furnished, 
then the astronomical transit, capable of being used in any meridian, should be 
furnished; but this is more cumbersome to be set up, and is not recommended. 
Either instrument should be especially constructed for use at very low tempera- 
tures. 
2d. Pistar’s & Martin’s Prismatic Circle, or if not possible, the Sextant 
constructed by Fauth, No. 73 of this catalogue, price, $110. 
3d. The Artificial Horizons. 
4th. Four Box Chronometers. 
With these pieces of apparatus it is believed that a skillful observer can 
determine his position with all needed accuracy. The instructions to be followed 
in the use of these instruments are to be found in Chauvenet’s Practical Astron- 
omy, Nautical Almanac (U. S.), Bowditch’s 5-figure Logarithm Tables. 
In the determination of the errors of sextants and circles, reference should 
be made to the Memoir by Harkness, in the U. S. Naval Observation for 1869, 
Appendix I, page 51. 
On the use of the portable Transit, the Zenith Telescope, etc., if provided, 
see Hilgard and others, in the Coast Survey volumes of observations. 
The only purely astronomical work to which it is recommended that special 
attention be given will consist in observing the phenomena of shooting stars. 
In this class of work the principal point is the determination of the radiating 
point for each group of shooting stars that may be seen, for which purpose the 
observer needs to be supplied with a number of the blank charts of stars, pre- 
pared by Prof. H. A. Newton, or with an equivalent planisphere. 
EXTRA OBSERVATIONS. It is considered that the following important subjects 
should be recommended to the observer’s attention, viz: 
1. Magnetic Earth Currents. (See Nipher on Earth Currents, etc.) 
2. Tides. (Earthquakes and earth tremors of the feeblest kind.) 
3. Pendulum Experiments. 
4. Atmospheric Electricity. 
