( «5^5 ) 
efjupiters Satellites^ or the OcciiltaiioH of the Fixt Stars 
by the Moon, 
I do not pretend that thefe Inftruments are any other- 
wife ufeful in finding the Longitude, than by fnewing the 
exaft time of the Day or Nighty which is one thing ab- 
folutely neceffary in this matter. Neither indeed will 
they ferve without a well adjufted Pendulum- Watch, or 
Pocket- Watch, that will keep time exadly from one 
oblervation by the Meridian-Inftrument to another. Mor 
indeed are they ufeful on Shipboard, but only on Land, 
where they may remainfixM- -But on Head-Lmds, or any 
where on Shoar, they may be ufeful to the Seaman. And 
indeed (until better difcoveries are made) thefe Meridian- 
Inflruments may be of ufe^where-ever longTelelcopes can 
be ufed, for feeing the Appulfes of the Moon to the fixt 
Stars, or the Eclipfes of Jupiter s Satellites ^ which is only 
on Land, llnlefs (which I have thought feafible) a con- 
venient Standing for a Man, and a Telefcope might be 
hung penduloufly in a Ship, which (efpecially in a calm 
Sea) may be aslittle fubjeft to difturbance, as the Pendu- 
lums of Watches are, which will retain their motion at 
Sea. 
5thly, You may with all exaftnefs continue a Meridian 
Line for many miles, by looking thro' either Sight, and 
feeing what Objects are interfered by the Plumb-lines. 
6thly, Thefe Inftruments are prepared with little coll:, 
or trouble : and eafily carried about, or imitable in any 
Place, the latter efpeciaJly,which may be madepacketable, 
or foon gotten. 
PPPPPPPPP. 
IV. A 
