A Plan for making a minute Survey of the Heavens. 45 



lost in bending the tail is much surpassed by the force gained 

 in the returning stroke. The returning stroke produces a force 

 which may be resolved into two ; one lateral, and the other in 

 the direction of the animal's motion. 



Decimus. 



VII. Statement of a Plan for making a minute Survey of the 

 Heavens and for the Formation and Publication of some new 

 Celestial Charts under the Superintendence and Direction of 

 the Royal Academy of Sciences at Berlin*. 



Advertisement. 

 r I "'HE Council of the Astronomical Society are happy in be- 

 •*■ ing able to lay before the members, a plan which has been 

 suggested for a minute survey of the heavens; — a grand desi- 

 deratum in modern astronomy ; — and, in fact, one of the prin- 

 cipal objects for which this Society was originally established, 

 and which it has constantly laboured to promote. 



The plan, here alluded to, appears to have originated with 

 M. Bessel, who has himself observed upwards of 32,000 of the 

 smaller stars, situated between 15° north and 15° south decli- 

 nation. With a view to render the survey of this zone of thirty 

 degrees more perfect (so as to comprehend many other stars 

 not yet observed by him or by any preceding astronomer), it 

 is proposed that it should be divided into 24 equal parts ; each 

 part containing l h in JR. And that every person, who is dis- 

 posed to take a share in the undertaking, should devote him- 

 self to a minute examination of all the stars situated in that 

 portion of the heavens which may be allotted to him : — 1°. by 

 reducing to the year 1800 all the stars hitherto observed in that 

 district ; and laying them down on a chart of given dimensions : 

 — 2°. by inserting also on the same chart, from estimation by 

 the eye, or from actual observation with an instrument, all the 

 remaining stars (to the 9th and 10th magnitude) that have 

 escaped the observation of preceding astronomers. 



In order to prevent any confusion in the distribution of 

 these portions of the heavens, it has been thought proper that 

 the whole plan should be placed under the superintendence 

 and direction of the Royal Academy of Sciences at Berlin : and 

 they have accordingly issued a Prospectus, giving a detail of 

 the plan proposed. A copy of that prospectus was forwarded 

 to the Astronomical Society: but some of the parts requiring 

 explanation, Mr. Herschel was requested to obtain further in- 

 formation on those points which appeared to be ambiguous. 



* The above paper has been circulated by the Astronomical Society. 



In 



