Suggestions for ImioTovement of Mariner's Compass. 79 



Akt. XX y. — On some HydraiiliG Clock-weights. By 

 F. MacGeoege, Esq. 



[Contributed 12tli June, 1871.] 

 This was an oral description, illustrated by a diagram of 

 a method of winding up turret clock -weights by water 

 power. The principal features in the proposition were, an 

 arrangement by which water was admitted into a cylinder 

 as soon as the clock-weights had descended to a certain level. 

 The piston was thereby raised, lifting the clock-weights the 

 length of its stroke again ; so soon as the weights reached 

 their highest position, the inlet valve was closed and outlet 

 opened, when the piston would fall to the bottom of cylinder, 

 leaving the weights free to act on the clock. The winding 

 up of the going barrel of the clock was done by a counter- 

 poise weight sufficient to draw back the barrel against the 

 friction of the spindle and ratchet click. The fall of the 

 weight would be of course regulated by the stroke of the 

 piston, and the writer proposed that a fall of one or two 

 hours would probably be found most convenient in practice 

 for ordinary turret clocks. 



Art. XXVI. — Suggestions for the Improvement of the 

 Mariners Compass. By E. J. White, Esq. 



[Eead, 12th June, 1871.] 



The recent loss of the Queen of the Thames steamship, 

 owing, in a great degree, it is said, to the erroneous action 

 of the compasses, has led me to consider whether an 

 improvement could not be made in ' what I may term the 

 mathematical part of the subject ; that is in the division 

 and notation of the card. The present system was adopted 

 at a time when the compass was supposed to point always 

 to the true north, and was, perhaps, under this condition 

 simple enough for the purpose. We have now, however, so 

 many corrections to be applied to the reading of the com- 

 pass before we can determine the true course, that it is quite 

 astonishing how the present cumbrous method should have 

 held its ground so long. The system of dividing circles, 

 which have to be read round the whole circumference, into 

 quadrants, or semi-circles, has been abandoned by astro- 



