Description of an Improvement in Jury Masts. 347 



REMARKS. 



In the model in the Society's possession the main mast h 

 broken about one-third of its length above the deck, proper 

 partners are secured on the deck, in which a hand mast and 

 spare main top mast are fixed on each bide of the broken 

 main mast, and secured thereto by two spare caps, morticed 

 on a square made in its centre. A strengthening cap, move- 

 able on these additional masts, connects them, and the 

 upper parts of these masts are secured firmly by trustle trees 

 j-n the main top. The foot of a spare fore top mast passes 

 through a cap made from strong plank, morticed into the 

 heads of the two temporary masts above mentioned, goes 

 through the main top, and rests in the moveable strength- 

 ening cap, which connects those- two masts, and enables 

 the fore top mast to be raised to any height which the main 

 top will admit, and be then firmly secured by the upper cap, 

 the main top, and the strengthening cap below it. The 

 fore top mast being thus adjusted, the cross trees and top 

 gallant mast are mounted upon it^ which completes th$ 

 whole business. 



Two cap? are the only things necessary to be made ex- 

 pressly for the purpose, the other articles being usually ready 

 en board the ship. 



Reference to the Drawing of Capt. Bolton's Jury Mast, 

 Plate X. Figs. 1, 2, 3. 

 Figs. 1, 2, and 3, where A A represents the partners or 

 pieces of timber which are bolted to the quarter deck for the 

 mast to rest upon. 13 is the stump of the lower mast, which 

 is cut square at the top, and of the same size as the head 

 of the mast originally war. ; upon this square, the main and 

 spare lower caps a a are fixed ; two mortices must be cut in 

 the partners A A to receive squares made at the lower ends 

 of the two temporary masts D D, which are supported by 

 the caps aa; one of them is a spare main topmast, the 

 other a hand mast ; these two support the main top E, ad- 

 ditional squares being made on the trustle trees to receive 

 each of them, h is a cap shown in fig. 2, made of four-inch 

 plank doubled for the purpose, and fitted upon the heads of 



the 



