676 
NATURE 
[May 19, 1923. 
The Tercentenary of Sir William Petty. 
ol the founders of the Royal Society, Wilkins was 
born in 1614, Goddard and Seth Ward in 1617, 
Evelyn and Bathurst in 1620, Willis in 1621, and Petty 
in 1623. Boyle and Wren were somewhat younger, 
being born in .1627 and 1632 respectively. Petty, 
whose tercentenary occurs on May 26, was thus thirty- 
seven years of age when the Society was inaugurated, 
and had already given evidence of great administrative 
powers. Unlike most of his fellow scientific workers, 
his education was gained mainly on the Continent, and 
he was a man of twenty-four or twenty-five when first 
he settled at Oxford. He was born at Romsey in 
Hampshire, the son of Anthony Petty, a clothier, and as 
a boy attended the Romsey Grammar School. From 
there at the age of fifteen, with a consignment of his 
father’s goods, he crossed to France, where he entered 
the Jesuit College at Caen, apparently maintaining him- | 
self by the sale of his father’s merchandise. 
From Caen, Petty returned home, served for a short 
time in the navy, but at the outbreak of the Civil War 
went abroad again, spent some time at Utrecht and 
Amsterdam, and in 1644 matriculated as a student of 
medicine at Leyden. He is next found in Paris, 
becoming known to Hobbes, Sir Charles Cavendish, and 
other English refugees, and attending the meetings of 
Mersenne, from which ultimately sprang the Paris 
Academy of Sciences. Once more at home he took up 
his father’s business, invented a process for duplicating 
letters, and in 1648 published his tract on education, 
“ Advice to Mr. Samuel Hartlib, for the Advancement 
of Some Particular Parts of Learning.” He proposed 
the establishment of a College of Tradesmen, with 
botanical theatre, observatory, etc., the members of 
which ‘‘ would be as careful to advance arts, as the 
Jesuits are to propagate their religion.” 
Petty next removed to Oxford, where he was able to 
associate with the philosophers who during those 
troublous times kept the lamp of science burning. 
Many of the meetings which Wilkins and Boyle fre- 
quented were held at Petty’s lodgings. In 1649 he 
took his doctor’s degree in physic, and a year or two 
later became professor of anatomy. 
From Oxford Petty was now sent by the Common- 
wealth Government to Ireland as physician general to 
the forces, where he quickly added to his reputation 
by reorganising the medical services. The terrible 
massacres of 1641 had by this time been ruthlessly 
avenged by Cromwell, and all who could not prove 
“consistent good affection ” to the English Government 
were to be dispossessed of their lands. This resulted in 
some 3000 native landowners losing their property. 
To Petty was given the task of measuring and surveying 
the forfeited estates. 
large scale and in a scientific manner, is curiously known 
as the “ Down Survey” because it was measured 
“down” on maps. Besides this, Petty also made a 
map of Ireland, completed about 1673, largely at his 
own expense. By his work in Ireland Petty himself 
gained considerable estates in Kerry and later on set up 
ironworks, opened lead mines and marble quarries and 
started a timber trade. His duties were not carried 
through without gaining for him many enemies, and in 
NO. 2794, VOL. 111 | 
His survey, which has been | 
described as the first attempt to carry out a survey ona | 

the last Parliament of the Commonwealth he was im- 
peached and for a time his fortunes hung in the balance. 
With the Restoration, Petty, who disliked extremists 
of all parties, was received favourably by Charles II. and 
was confirmed in the possession of his Irish estates. He 
now was able to resume the society of his scientific 
friends, and he was present at Gresham College on 
November 28, 1660, when the Royal Society was 
formed. He became a member of the first council and 
often contributed papers to the Proceedings of a prac- 
tical nature. He is several times mentioned in con- 
nexion with the subject of shipping, and in 1662 made 
some stir by the mention of a double-bottomed or twin- 
hulled boat which would go against wind and tide. A 
ship constructed to his plans made two voyages be- 
tween Dublin and Holyhead and was then wrecked. 
The idea has been put into practice several times since 
the days of Petty, notably so in the case of the channel 
steamer Calais-Douvres constructed in the ’eighties of 
last century. At one meeting of the-Royal Society Petty 
‘“‘was intreated to inquire in Ireland for the petrifi- 
cation of wood, the barnacles, the variation of the com- 
pass, and the ebbing and flowing of a brook.” Among 
his other services to the science of his day was the part 
he took in the foundation of the Dublin Philosophical 
Society in 1684, of which he was president. Hedrew up 
for the Society a ‘‘ Catalogue of mean, vulgar, cheap 
and simple experiments,” and among his advice to 
the members was “that they carefully compute their 
ability to defray the charge of ordinary experiments 
fforty times per annum, out of their weekly contribu- 
tions, and to procure the assistance of Benefactors for 
what shall be extraordinary, and not pester the Society 
with useless or troublesome members for the lucre of 
their pecuniary contribution.” 
Petty was full of worldly wisdom and possessed what 
Benjamin Martin called a “ universal practical genius.” 
One result of this was that he died a very rich man. But 
at a time when such studies were rare he wrote on taxes, 
revenue, the origin of wealth, trade, population, and the 
growth of cities. It is on his work as a political 
economist that his reputation rests. He condemned the 
farming of the revenue of Ireland, suggested free com- 
mercial communication between that country and 
England, and consistently urged upon the Government 
the necessity of a department for the collection of 
statistics. He co-operated with John Graunt, another 
original member of the Royal Society, in the production 
of a book entitled “ National and Political Observa- 
tions . . . made upon the Bills of Mortality,” published 
in 1662, which may be regarded as the first book on 
vital statistics ever published. 
A tall handsome man, Petty was known among his 
fellows for his unusually good temper. Evelyn said of 
him “‘ there was not in the whole world his equal for a 
superintendent of manufacture and improvement of 
trade, or to govern a plantation,’ and Pepys refers to 
the charm of his society. Knighted by Charles in 1661, 
Petty in 1667 married a daughter of Waller the regicide, 
and was survived by three children. He twice refused 
a peerage, but his widow was created Baroness Shel- 
burne. He died in Westminster on December 16, 1687, 
and was buried in the Abbey Church at Romsey, i 
