TRANSACTIONS OF THE SECTIONS. 21 



force, while in the afternoon hours we have an increase of those components. 

 3. Both outbreaks of both storms tended, on the whole, to diminish both com- 

 ponents of the force, aud to increase the westerly declinatiou, — a somewhat uncom- 

 mon type of disturbance. 4. Both these storms were accompanied by phenomena 

 on the surface of the sun which are worthy of notice. At the time of the occur- 

 rence of the great disturbance of August-September 1859, a very large spot might 

 have been observed on the disk of our luminary, and several of a size somewhat 

 smaller. Considerable changes were taking place in the appearance of these spots, 

 and, moreover, a luminous body was observed, by Carrington and Hodgson inde- 

 pendently, to move across the large spot at the very moment when the magnetic 

 disturbance broke out at Kew. On the 29th of July, 1865, there was no spot or 

 almost none on the sun's disc ; but on the 3rd of August there was a very consider- 

 able spot on the right limb, nearly going off. The only pictures obtained at Kew 

 were on these days, and it is clear from these that this spot must have rapidly 

 formed between July 29 and August 3, on the right half of the solar disk. It 

 would, of course, be premature to conclude that certain changes going on in the 

 sun cause, or even invariably accompany, terrestrial magnetic storms ; but there 

 can be no impropriety in stating facts which may possibly serve to establish some 

 future generalization. 



An Improved Standard Barometer. By W. Symons. 

 At the Newcastle Meeting of the Association, the author exhibited a Standard 

 Barometer combining the advantages of Fortiu's and Gay-Lussac's instruments. 

 The objection that the contraction and bending of the tube necessary in the 

 arrangement for making that instrument portable impaired its sensitiveness, has 

 been entirely removed in this improved one. The facility of reading is also in- 

 creased. 



Hydrostatics. 



On the Hydrometer and its Adaptation to the present requirements of the 

 Board of Inland lievenue. By L. Oeetling. 



In this paper the means adopted for levying the duty upon spirits in the Bevenue 

 departments were considered, and attention called to the shortcomings of the present 

 method. The instrument now used is Sikes's hydrometer, accompanied by Sikes's 

 tables. It was distinctly pointed out that the instrument and the tables had been 

 constructed upon different formula?, and were not in harmony, and that, further, 

 there were defects in the actual form of that hydrometer, causing considerable 

 amounts of error in the estimation of the strength of the spirits tested by it. 



Instruments. 

 On a Self-recording Anemometer. By S. B. Howlett. ' 



On the Topograph, a neiu Surveying Instrument By Captain Lendy. 



The topograph may be used — 



1. As a prismatic compass alone ; 



2. As a plane table alone with its sight ruler ; 



3. As a plane table and a compass, combined to facilitate the finding of sta- 

 tions. 



It possesses the great advantage that it maybe employed without any alteration, 

 simultaneously or successively, as a plane table or a compass, when in the same sur- 

 vey we pass from undulating ground to open country, and rice versd. In all cases, 

 we need no scales, no pair of compasses, and no protractor, the machine itself pro- 

 tracting the angles and laying down distances at the scale. 



