Ruschenberger.] ' a [May 15, 



suppressed Mr. Logan's letter, and communicated the description of God- 

 frey's quadrant to Hadley, a mathematical instrument maker in London, 

 who, after making slight mechanical changes in the instrument, obtained 

 a patent for it. In this way Godfrey's invention came to be unjustly 

 called Hadley's quadrant. 



Dr. Emerson establishes Godfrey's right to priority of invention on the 

 testimony of James Logan, Benjamin Franklin, Peter Collinson and 

 others. 



Thomas Godfrey was born in Bristol township, near Germantown, on 

 his father's farm of 150 acres, in 1704, and died in 1749, and was buried 

 there.* He was fairly educated, and was a member of Franklin's famous 

 Junto. He taught himself to read Latin. 



Mr. John F. Watson, the annalist, convinced of the wrong done to God- 

 frey, sought his grave, ascertained the inscription which had become illegi- 

 ble on the gravestone, and in 1838, at his own expense, had the remains 

 with those of his wife, father and mother transferred to Laurel Hill 

 Cemetery. 



The Mercantile Library Association and certain inhabitants of German- 

 town jointly contributed means to erect a monument to Godfrey, the 

 completion of which was the occasion of Dr. Emerson's address. 



Possession of several hundred patrimonial acres in Kent county, Del., 

 accounts for his attention to agricultural affairs. He made numerous and 

 extensive experiments to ascertain the comparative value of different fer- 

 tilizers. He erected a building on Frankford creek, Philadelphia, in 

 which was manufactured, under the direct management of a Frenchman 

 named Jourdan, a fertilizer called Jourdan's phosphate. This product 

 was extensively used during several years. In 1844 or '45, two tons of Peru- 

 vian guano were brought to Philadelphia as a sample. At his suggestion he 

 and his friend, Mr. D. B. Cummins, purchased each a ton and introduced it 

 to the farmers of Delaware. On one of his farms he constructed a mill for 

 crushing bones by horse power. The work was imperfectly done ; but 

 by treating the crushed bones with sulphuric acid and mingling the pro- 

 duct with ashes and fine earth a fertilizer was produced which proved to 

 be a good substitute for Peruvian guano, and cost much less. By obser- 

 vation and experiment he ascertained, in 1849, that the delightful and pe- 

 culiar flavor of our so-called grass butter is due to the sweet-scented ver- 

 nal grass Anthoxanthum odoratum which flourishes in pasture fields till 

 about the end of May, and upon which the cows feed. He obtained from 

 this sweet vernal grass an essential oil, and ascertained that it contains 

 lenzoic acid, upon which its flavor depends ; and that a small quantity of 

 benzoin acid administered to a cow imparted to the butter made from her 

 milk the same flavor it has while sweet vernal grass forms part of her 

 feed.f He delivered appropriate addresses before horticultural and agri- 



* Watson's "Annals of Philadelphia." 



t See, Letter, Oct. 31, 1849, from Dr. Emerson to the Commissioner of Patents. Report 

 of the Commissioner of Patents for the year 1849, Part ii Agriculture pp. 372-75. 



