ecuring rotary motion without using the crank, but
eventually he adopted the "Sun-and-planet motion," the invention of
Murdock. This had the singular property of going twice round for every
stroke of the engine, and might be made to go round much oftener
without additional machinery. The invention was patented in February,
1782, five Years after Murdock had entered the service of Boulton and
Watt.

Murdock continued for many years busily occupied in superintending the
Cornish steam-engines. We find him described by his employers as
"flying from mine to mine," putting the engines to rights. If anything
went wrong, he was immediately sent for. He was active, quick-sighted,
shrewd, sober, and thoroughly trustworthy. Down to the year 1780, his
wages were only a pound a week; but Boulton made him a present of ten
guineas, to which the owners of the United Mines added another ten, in
acknowledgment of the admirable manner in which he bad erected their
new engine, the chairman of the company declaring that he was "the most
obliging and industrious workman he had ever known." That he secured
the admiration of the Cornish engineers may be obvious from the fact of
Mr. Boaze having invited him to join in an engineering partnership; but
Murdock remained loyal to the Birmingham firm, and in due time he had
his reward.

He continued to be the "right hand man" of the concern in Cornwall.
Boulton wrote to Watt, towards the end of 1782: "Murdock hath been
indefatigable ever since he began. He has scarcely been in bed or
taken necessary food. After slaving night and day on Thursday and
Friday, a letter came from Wheal Virgin that he must go instantly to
set their engine to work, or they would let out the fire. He went and
set the engine to work; it worked well for the five or six hours he
remained. He left it, and returned to the Consolidated Mines about
eleven at night, and was employed about the engines till four this
morning, and then went to bed. I found him at ten this morning in
Poldice Cistern, seeking for pins and castors that had jumped out, when
I insisted on his going home to bed."

On one occasion, when an engine superintended by Murdock stopped
through some accident, the water rose in the mine, and the workmen were
"drowned out." Upon this occurring, the miners went "roaring at him"
for throwing them out of work, and threatened to tear him to pieces.
Nothing daunted, he went through the midst of the men, repai