320 Davis’s Report on the Nautical Almanac. 
stars of comparison, which were used in the reduction of those 
observations of the planet Mars which have been made during 
the last hundred. years at the Greenwich observatory ; to test by 
immediate observations the accuracy of the elements of the new 
planet Iris; to furnish from the records of the observatory certain 
observers towards the new planets discovered since the year 1827, 
concerning which astronomical history supplies, of course, no in- 
ormation, and concerning which all our knowledge is to be 
gleaned from future observation. 
But it is the printed and published transactions of this and other 
observatories, in which the observations, &c., are given to the 
world in their reduced and complete and final form, that are em- 
ployed im the large computations of the almanac, and not the 
separate observations made at the various instruments from day 
to day, in the prosecution of a great scientific enterprise. 
What erpenses are necessary therefor, except the pay of the 
superintendent ? oe 
The pay of computers, the cost of publication, including com- 
position, press-work and correction, paper, books, &c., &c., the 
expense of stereotyping, the printing of auxiliary tables for com-— 
putation, of blanks, of instructions, and mathematical formulas: 
and methods. . 
4. What progress has been made towards making a Nautical 
Almanac? 
The first volume is nearly completed, and its printing far ad- 
vanced. All the main and heavy computations are done. 
he progress of the printing, é&c., is necessarily slow, becatise 
forms which are to be permanently adopted, are now for the first 
time decided upon, and because in a work of such a character, 
which is destined essentially to add or to detract from the scien- 
tific reputation of the nation, it is advisable to proceed with the 
utmost care and circumspection. 
5. For how long a period the calculations of the frst almanac 
are expected to extend ? oa 
For a period of one year; the first number of the almanac will 
be published in the year 1852, for the year 1855. 
6. Whether it is necessary to the perfection of the Nautical 
Almanac to make observations at more than one observatory ; a 
uf so, are they made at two observatories ; and if so, at what two? 
_ The reply to this question is partly comprised in the reply ved 
the first question ; but it should, perhaps, be more explicitly said 
that no vatory, neither that at Washington nor that at Var of 
bridge, as has been suggested, receives any portion whatever 0° 
