“ effect o f their united attractions : but this even muff have been
“ very infenftble ; fmce, according to the higheft eitimate admif-
“ fible, the lum o f all the mountains from which any effeét might
“ be fufpeCted, cannot be greater than a cubic league. Now this
“ mafs being fuppofed o f a deniity double the mean denlity o f thé
“ earth, and its center o f attraction at five leagues diitance from
“ Kittifvaza, and ten from Tornea, could not produce on the
“ plumb-line a greater deviation than o".3438 at Kittifvaza, and
“ 0".036g at Tornea; whence it follows, that the total effeCt o f
“ this alteration could have been only o".4298, and confequently
“ the correction which ought to be made in the length o f a de-
“ gree o f the meridian, fuch as has been meafured by the French
“ academicians, would be only 6". 357 5 to be added inftead o f a
“ hundred toifes, which it has been fuppofed ought to be deduCted.
“ I believe, then, I may affirm, that on my part there can be no
“ fufpicion o f an error as to this fubjeCt, and that there is truly
“ fome error in the meafurement o f 1 736 : the caufe o f this may
“ be fairly attributed to a defeCt in the fextant or quadrant, or
“ perhaps, which is no lels probable, to fome uncertainty in the
“ bafe. Upon the whole, in order to fettle all thofe doubtful
“ circumftances, it feems abfolutely neceffary that this meafure-
“ ment ffiould be wholly executed anew.”
“ T o all this, give me leave to add one remark, which I had
“ occafion to make at Tornea, and which, I imagine, well merits
“ the attention o f the learned.
S‘ W e know that the French aftronomers determined, at each
“ ftation,
“ ftation, the elevation or depreffion o f the other fignals in rela-
“ tion to their horizon. I meafured all thofe angles, and what
“ furprifed me a good deal was, that I found them always a little
“ larger than they have been determined in the figure o f the earth.
1 The inftrument I employed in my operation was a whole circle
“ o f fourteen inches and two-thirds diameter, graduated at each
I minute: neverthelefs, 1 believe, that by the help o f an eftimate,
I one may allure himfelf that he is not deceived by more than
I ten, or at moft fifteen feconds. A complete defcription o f this
inftrument may be feen in the memoirs o f the academy o f
“ fciences, at Stockholm, for the year 1750, 26 th and following
pages. T he firft fufpicion that ftruck my mind, upon obferv-
| ing this difference, was, that it might arife from the point zero
ic in that circle. This I examined on the fpot, and found it wrong
“ l' 30 . I continued the lame examination for feveral fucceffite
“ days after I got to Tornea; and taking the mean o f my obfer-
“ vations on terreftrial objedts, as w ell as meridian heights o f the
“ fun, I obierved that i f 24" ought to be dcdudled from all the
“ obfervations o f heights, a circumftance which at the fame time
“ proves that the inftrument had fuffered no injury in travelling.
“ Individuals will make what remarks they pleafe on my obler-
“ vations ; I here fubjoin them exadlly as they were made.