258 Mr. Meikle on an improved Syphon-Hydrometer. 



which has most northern declination, through east, south and 

 west, to 360 degrees. The immersions happen, therefore, with 

 few exceptions in the two first quadrants, and the emersions 

 in the two last. 



After the occultations of stars follow the mean places of 

 the stars occulted, taken from Baily's Catalogue, and so ex- 

 pressed as they are wanted in the calculation of the occultations, 

 which forms the subject of another part of this book*. 



The auxiliary tables which then follow will be explained in 

 the paper just alluded to. The horizontal equatorial parallax 

 here given, belongs to the moment of the moon's culmination ; 

 and the quantities Aa and A I added to the mean place of a 

 star for 1830, give very nearly the apparent place of each star 

 which can be occulted by the moon. 



The uncertainty about the extent of the calculation and 

 the distribution of the different parts, however worthy of a 

 place in this almanac, has caused such frequent changing and 

 copying, that possibly some single errors may thereby have 

 been introduced. Should, therefore, some erroneous data oc- 

 cur, (for the communication of which I shall be very thankful,) 

 I request that the blame may not be laid on the labours of 

 my coadjutors, who have performed their part of the work with 

 great sacrifices. Every imperfection which may be pointed out, 

 and every improvement both in form and matter which may 

 be suggested, shall be duly attended to. 



The typographical beauty of the printing, a production of 

 the Academical Press of this city, which has been carried to a 

 high degree of perfection by a great sacrifice on the part of 

 the whole Academy, and particularly of an individual member 

 of it, one of those whose services are most in request, — will, it 

 is hoped, satisfy every one as a worthy accompaniment, without 

 laying any claim to ornament or splendour. On a close ex- 

 amination, judges in these matters will not fail to perceive the 

 careful management of the superintendent of the press, who 

 has spared no pains in the first arrangement to give all the aid 

 of his experience to the execution of my wishes. 



XLV. On an improved Syphon-Hydrometer. By Mr. Henry 

 Meikle f. 



T N the Philosophical Magazine for September 1 8 26, (vol. lxviii. 



p. 1 66) I proposed an instrument to be used as a hydrometer, 



consisting of an open glass tube thrice bent, so as to have four 



* The part of the Ephemeris here mentioned, will probably appear in 

 a future Number of the Phil. Mag. and Annals.— Edit. 

 f Communicated by the Author. 



straight 



