The construction of the wonderful canon of logarithms

xvi
Introduction.
generally believed to have been Napier's friend, Dr
Craig. The computation of the Table or Canon, and
the preparation of the two works explanatory of it,
the Constructio and Descriptio, must, however, have
occupied years. The Canon, with the description of its
nature and use, made its appearance in 1614. The
method of its construction, though written several years
before the Descriptio, was not published till 161 9.
Napier at the same time devised several mechanical
aids to computation, a description of which he published
in 1 6 1 7, ' for the sake of those who may prefer to work
with
the natural numbers,' the most important of these
aids being named Rabdologia, or calculation by means
of small rods, familiarly called ' Napier's bones.'
The invention of logarithms was welcomed by the
greatest mathematicians, as giving once for all
the longdesired
relief from the labour of calculation, and by none
more than by Henry Briggs, who thenceforth devoted
his life to their computation and improvement. He
twice visited Napier at Merchiston, in 161 5 and 1616,
and was preparing again to visit him in 1.6 17, when he
was stopped by the death of the inventor.
The strain
involved in the computation and perfecting of the Canon
had been too great, and Napier did not long survive its
completion, his death occurring on the 4th of April 161 7.
He was buried near the parish church of St Cuthbert's,
outside the West Port of Edinburgh.
It has been stated that Napier dissipated his means
on