the Trigonometrical Operation. l r , 
an operation of fo delicate and difficult a nature could not have 
been effected. 
The apparatus for the meafurement of the bafe with the flee l 
chain, notwithftanding the urgency of the cafe, was not lent 
to its deftinafion until tne end of the firft week of October. To 
Lieut. Fiddss the engineer, was then joined Lieut. Brycs of 
the Royal Artillery; and it was not before' the beginning of 
December, that thefe two gentlemen, with the molt unremit- 
ting labour and perfeverance, were able to accomplifn the mea- 
furement, as will be feen in the detailed account of that ope- 
ration given in the firft fedlion of this Paper. 
In finilhing the co-operation with the French Commiffioners, 
at Lydd on the 17th of October, our inftrument had now 
pafled through fixteen ftations out of twenty-three. There of 
courfe remained yet feven Rations where it was to be placed, 
and obfervations to be made. Eagerly wilhing to bring the bull- 
nefs to a conclufion, we ftruggled on through five of the feven. 
But the weather at length became fo tempeftuous, that it was 
utterly impolfible to continue it, with any hopes of being able 
to make latistacrory obfervations. Perched on the tops of high 
fteeples, fuch as Lydd and Tenterden, or on heights, fuch as 
Hollingborn Hill, we fufficiently experienced, that operations 
of this foit, where the moft important obfervations could only 
be made at night, by means of the white lights, Ihould never 
be undertaken in the latter feafon. 
On the fecond of November, the inftrument was accord- 
ingly removed from the top of Hollingborn Hill, and fent to 
town, leaving the Rations on Goudhurft and Frant Churches, 
both likewife fituated on eminences, unoccupied until the en- 
fuing feafon. 
Q.2 
The 
