The Ramsey Observatory. 447 



wood covering the part where these shutters meet will keep out 

 the rain ; the only place where it might come in is at the ex- 

 treme apex, and to prevent it a round disk of zinc must be put 

 on under the knob, bat high enough above the upper ends of 

 the rafters to allow the triangular shutters to open. The writer 

 has constructed his shutters in four pieces, hinged two and two 

 together, so that he can open them from eighteen inches to six 

 feet. 



The roof being completed and well painted inside and out, 

 is ready for lifting on, which can be done bodily ; but first the 

 gear for causing it to revolve must be contrived. For this 

 purpose eighteen iron sash-rollers of good size must be got 

 from any good ironmonger. Twelve of these must be sunk in 

 the plates of wood on the top of the posts, and just over them. 

 The other six rollers must be attached to some stout blocks of 

 wood, so as to revolve vertically, and these blocks will be 

 screwed to the plate, between the posts, in alternate spaces, so 

 that when the roof is on, the inner edge of the great ring or 

 circle touches, or may touch them, to prevent the roof going 

 off sideways. The twelve rollers should be well oiled, and they 

 will be found to bear the roof, and allow it to revolve with a 

 very moderate force. 



The shutters must have a bolt to keep them shut ; and 

 about four bent pieces of iron driven into the top of the posts, 

 with a sort of hook projecting a little over the inner edge of 

 the great circle of the roof, will keep it from being lifted by the 

 wind. 



It only remains to remark that the extreme dryness of this 

 building arises from its being raised a foot clear from the 

 ground, but it is better and warmer if roofing-felt be nailed on 

 inside the boards. Some very cheap stuff, cotton or linen, etc., 

 nailed inside the felt will receive the paper which, with a 

 simple cornice, finishes the interior. 



The weather-boards outside can be tarred over or painted 

 roughly, and where loppings of oak can be had, some of the 

 crooked branches put on in a gothic pattern produce a very 

 pleasing effect. The eaves can be ornamented according to 

 taste or local facilities. 



The following is an estimate for materials and labour on a 

 high computation, not including the pedestal of the telescope ; 

 but in most parts of the country, especially where English fir 

 can be obtained, and the wages of a carpenter are less than five 

 shillings a day, a considerable saving may bo effected, so that 

 the expense of this pretty little building will vary from seven 

 to ten pounds, according to local circumstances : — 



