414 FIRST REPORT UPON MAGNETIC WORK

" Having made many and diverse compasses, and using alwaies to
finish and end them before I touched the needle, I found continuallie
that after I had touched the yrons with the stone, that presentlie the
North point thereof woulde bend or decline downwards under the
horizon in some quantitie; insomuch that to the flie of the compass,
which was before levell, I was still constrained to put some small piece
of ware on the South point and make it equall againe. Which effect
having many times passed my handes without anie great regard there-
unto, as ignorant of anie such propertie in the stone, and not before
having heard nor read of anie such matter, it chaunced at length that
there came to my hands an instrument to be made with a needle of
sixe inches long, which needle after I had polished, cut of a just
length, and made it stand levell upon the pin, so that nothing rested
but onlie the touching it with the stone, when I had touched the same,
presentlie the North part thereof declined down in such sort that being
constrained to cut awaie some of that part to make it equall againe, in
the end I cut it too short, and so spoiled the needle wherein I had
taken so much paines. Hereby being stroken into some cholar, I
applied myself to seeke further into this effect, and making certaine
learned and expert men, my friends, acquainted in this matter, they
advised me to frame some (instrument to make some exact triall how
much the needle touched with the stone would decline, or what greater
angle it would make with the plaine of the horizon.

" Whereupon I made diligent proofes, the manner whereof is shewed
in the chapter following."

Norman then proceeds to describe the instrument with which he
determined the " declining " or dipping of the north end of the needle
below the horizon. He found a dip of 71° 50'.

George Hartmann, of whom we have already spoken, had observed
this dipping of the needle previous to Norman, in 1544 at Nurem-
burg, but he failed to make a precise determination, the value which
he gave being about one-sixth of the true value at that time.

discovered by Robert Norman. London, 1576. Reprinted and attached to
William Whiston's The Longitude and the Latitude found by the Inclina-
tory or Dipping Needle. London, 1721. We trust that this book will like-
wise form one of Hellmann's reprints.