184 Proceedings of the Royal Society of Edinburgh. [Sess. 
Volumes 5 and 6 contain the logarithms to 28 figures of all numbers 
up to 20,000. 
From these the succeeding thirty -two volumes are constructed, giving 
the logarithms to 15 places of all numbers from 100,000 to 370,000. 
This colossal work must ever remain of the greatest value to computers 
of logarithmic tables. It is a great national possession. 
The other Tables in the collection are trigonometrical and astronomical. 
Of special interest are the Tables of Sines and Tangents calculated according 
to the centesimal division of the quadrant. 
It is hoped that ere long some of these Tables may be published in some 
form, so as to make them more immediately accessible to computers. They 
are the foundation of Dr Sang’s published book of seven -place logarithms 
to 200,000, undoubtedly the most perfect of its kind ever printed. By 
placing the duplicate electrotype plates of this book along with the 
manuscript volumes in the custody of the Royal Society, with power to 
publish, the Misses Sang have given to the Nation every facility for 
publishing a new or even an extended edition of their father’s work. 
The complete account of the various tables follows, and the attention of 
the scientific world is now drawn to the importance of the collection in the 
custody of the Society. 
In the name of the British Nation, the Royal Society of Edinburgh now 
publicly thank the Misses Sang for their valuable gift, and, as custodiers of 
these manuscript volumes, undertake to do all in their power to make them 
of real use to the scientific world. 
The above statement was read by the Chairman at the First Ordinary 
Meeting of the Society, held on 4th November 1907. 
The following general account was drawn up in November 1890 by 
Dr Edward Sang himself : — 
“ These computations were designed and undertaken with the view to 
the change from the ancient subdivision of the quadrant to the decimal 
system, a change long desired, and destined inevitably to be made. One 
hundred years ago it was on the very point of being completed. Mathe- 
maticians were then engaged in the introduction of the decimal system 
into every branch of calculation and measurement ; but for the introduction 
of this new system into the measurement of angles, it was necessary to 
have a new trigonometrical canon. The French Government deputed 
M. Prony, with a large army of computers, to compile this new canon, and 
astronomers awaited with impatience the advent of this indispensable 
