USEFUL PROJECTS. 



873- 



scs lifted at Plymouth dockyard, 

 from tl)e 1st of January, 1798, 

 to the 31st of December, 1800, 

 and had the operation of lifting 

 taken less time, the number would 

 liave been very considerably in- 

 creased; for the saving of a day is 

 very, frecjuesitly the cause of savin;; 

 the sprin:;-tide, which makes the dif- 

 ference of a fortnight. The import- 

 ance of thi^ expedition in time of 

 war, cannot be sufficiently estimated. 



This invention may be applied 

 with great advantage, whenever it js 

 necessar}", to erect shores to sup- 

 port any great weight?, as, for in- 

 stance, to prop up a building during 

 the repair of its foundation, &c. 

 Captain Wells, of his majesty's ship 

 Glory, of 98 guns, used wedges of 

 Mr. Sepping's invention, for a fid of 

 a. top gallant-mast of that ship. In 

 1803, the top gallant-masts of the 

 Defence, of 74 guns, were fitted on 

 this principle by ?ilr. Seppings : and 

 from repeated trials, since she has 

 been cruising in the North Sea, tiie 

 wedge lids have been found in every 

 respect to answer. 



But it is ?vlr. Scppings's wish, 

 that it should be understood, that 

 the idea of applying his iiivention to 

 the lid of a top-gallant-mast, origi- 

 nated with captain Wells, who well 

 f undersiood the principle, and had 

 received from him a model of tlie 

 invention. 



When it is required to strike a 

 top.gall;int-mast. the top ropes arc 

 hove flglit, and the pin which keeps 

 th(! horizontal wedges in their place 

 is taken out by one man going aloft 

 for that jjurpose : the other hori- 

 zontal wedgi! is worked in the lid. 

 The upper jjart of the (id hole is cut 

 to form (he vertical wedge. 'I'lic 

 advantage derived from lidding top- 

 g'dllant^masts in this way is, that 



they can be struck at the short- 

 est notice, and Avithout slacking the 

 rigging, which is frequently thu 

 cause of springing and carrying them 

 away, particularly those wi(h long 

 pole heads. The angle of the ho- 

 rizontal wedges for the lids of mast?, 

 should be about twenty degrees. 



Account of the Processes for Dyeing 

 the beautiful Reds on the Curomcui- 

 dle Coast ; commimkated by J. 

 Muchlachlan, Esq. of Calcutta. 



The following receipts for dyeing 

 the beautiful reds of the Coroman- 

 del coast, were sent to me from Ma- 

 dras by a scientific friend, who had 

 the several operations detailed in 

 them performed in his own pre- 

 sence. I forwarded a copy of them, 

 and a small quantity of the ingre- 

 dients mentioned in them, to a friend 

 at home, several years ago ; but he 

 dying about or soon after the time 

 of their arrival, I never learned what 

 became of them. It strikes me, 

 however, that there is a considerable 

 coincidence between the thread pro- 

 cess and that which I have seen re- 

 commended by J\Ir. Henry of Man- 

 chester, for dyeing the Adrianople 

 or Turkey red. 



I am not certain whether it is 

 known at home, that many of the 

 hills ia Bahar, and other parts of 

 India, contain immense quantities of 

 mica, talc, or iNInscovy glass. The 

 natives of tliis country and China, 

 makc! very splendid lanterns, sliades, 

 and ornaments of it, tinged of vari- 

 ous fanciful colours ; and it is also 

 used by them in medicine. WIkmi 

 burned or calcined, it is, I am told, 

 considered as a specific in obstinate 

 coughs or consun>j)lioiis. When 

 powdered, it serves to filver the 



Indian 



