1(>4 Biographical Account of [March, 



and was settled as a clergyman in an episcopal congregation in 

 Philadelphia. He communicated the fact to Dr. Smith, Provost of 

 the College of Philadelphia : a friendship soon took place between 

 them, and Dr. Smith was at great pains to draw him into public 

 notice. 



In 1763 Mr. Rittenhou?e was employed by Mr. Peters, Pro- 

 vincial Secretary to the Governor of Pennsylvania, to determine 

 part of the limits between Maryland and Pennsylvania, which had 

 long been a subject of dispute between Lord Baltimore and Mr. 

 Penn, the proprietors of the respective provinces. This laborious 

 task he performed to the satisfaction of the parties concerned. 



In l/CG Mr. Rittenhouse married Eleanor Colston, daughter of 

 Bernard Colston, a reputable farmer in the neighbourhood. She 

 belonged to the society of Quakers. Mr. Rittenhouse had been 

 brought up an Anabaptist ; but he never declared himself a member 

 of any particular church. The marriage was solemnized at Nor- 

 riton by his brother-in-law, Mr. Barton. His father had previously 

 resigned to him his house and farm of Norriton, having removed 

 •with his family to a house that he had built on his place in Wor- 

 cester township. At Norriton Mr. Rittenhouse remained for four 

 years ; during which period his reputation as a mechanic and an 

 astronomer was very much increased by two circumstances, which 

 deserve to be particularly mentioned. The first was the construc- 

 tion of an orrery, much more complete than any thing of the kind 

 that had been previously contrived. It exhibited the true motions 

 of the different planets and satellites with the greatest exactness, so 

 as to show their place in the heavens, and their relative position 

 with respect to each other without any sensible error for thousands 

 of years to come. The relative position of these bodies for any 

 particular time could be determined by turning a winch till an 

 index on a dial plate pointed out the time wanted. Before he 

 attempted the construction of this expensive machine Mr. Barton, 

 his brother-in-law, bound himself to reimburse him for the expense, 

 provided he could not get it sold ; but as soon as the machine was 

 completed, there was a competition for it between the College of 

 Princeton, New Jersey, and the College of Philadelphia. The 

 orrery was disposed of to the College of Princeton for 300/. ; and 

 he made another within the year for the College of Philadelphia. 



The other circumstance was of still greater importance : it was 

 the observation of the transit of Venus in 1769. This transit, 

 being of rare occurrence, and being the best means of determining 

 the parallax of the sun, was eagerly expected by astronomers, and 

 had attracted the particular attention of almost all the crowned 

 heads in Europe. Philadelphia being a proper station for observing 

 this phenomenon, the opportunity was laid hold of by the Philoso- 

 phical Society of that city, and three committees were appointed to 

 make the observation in tliree different places : one of those was at 

 the observatory constructed by Mr. Rittenhouse at Norriton. The 

 committee appointed to make the observation in this place were 



