Page:A biographical dictionary of eminent Scotsmen, vol 5.djvu/31

Rh determining- the average quantity of rain which fell, by means of a funnel, the wider cylinder of which was thirty inches in diameter, and terminated in a pipe three inches in diameter, and ten in length; the latter being graduated in inches and tenths. Ten measures of the pipe being equal to one inch of the cylinder, one measure to one-tenth of an inch, one inch of the measure to one-hundred, and one-tenth to one-thousand part, the depth of any particular quantity of rain which fell might be set down in decimals with ease and exactness; and the whole, at the end of each month or year, summed up without any trouble. Shortly after, and probably in consequence of this invention, he was elected a fellow of the Royal Society, and commenced giving public lectures on hydrostatics, mechanics, and various branches of natural philosophy, at Morpeth, Alnwick, and Newcastle. His valuable apparatus for illustrating and explaining his lectures, after passing through various hands after his death, were, in 1821, deposited in the library belonging to the dissenters in Red Cross Street, London, being bequeathed to the public by Dr Daniel Williams. By manuscripts afterwards found among Mr Horsley's papers, it appears that about the year 1728, he conceived the idea of writing a history of Northumberland, and from the extensive design of the work which he had sketched out, embracing its antiquities, traditions, geological structure, &c., and his ability for the task, it is much to be regretted that he did not live to complete it. A map of the same county, commenced by him, was afterwards completed by Mr Mark, the surveyor employed by him, and published at Edinburgh in 1753. Mr Horsley also published a small book on experimental philosophy, in connexion with the course of lectures above noticed. His great work, however, by which his name will most probably be transmitted to posterity, and to which he dedicated the greater part of his short but busy career, is his "Britannia Romana," or the Roman affairs of Britain, in three books. This work is in folio, and consists of five hundred and twenty pages, with plates exhibiting maps of the Roman positions, copies of ancient coins, sculptures, inscriptions, &c. It is dedicated to Sir Richard Ellys, Bart., contains a lengthy preface, a chronological table of occurrences during the Roman domination, a copious index of the Roman names of people and places in Britain, &c. It was printed at London for John Osborne and Thomas Longman, &c., in 1732; but Mr Horsley lived not to see the fate of a work which had unceasingly engrossed his time, thoughts, and means for several years. His death took place at Morpeth, on the 15th January, 1732, exactly thirteen days after the date of his dedication to Sir Richard Ellys, and while yet in his 46th year. The enthusiastic ardour with which he devoted himself to this work, may be gleaned from the following passage in the preface: "It is now four years since I was prevailed with to complete this work, for which time I have pursued it with the greatest care and application. Several thousand miles were travelled to visit ancient monuments, and re-examine them where there was any doubt or difficulty." He also went to London to superintend the progress of his work through the press, and engaged in an extensive correspondence on the subject with many of the most learned writers and antiquaries of the day. The " Britannia" is now a very rare work, and it would appear that the plates engraved for it are entirely lost. Mr Horsley was married early in life to a daughter of a professor Hamilton, who, according to Wood, in his Ancient and Modern State of Cramond, was at one time minister of that parish. By her he had two daughters, one of whom was married to a Mr Randall, clerk in the Old South Sea House, London; the other to Samuel Halliday, esq., an eminent surgeon at Newcastle. From a passage in his manuscript history of Northumberland, it would also appear that he had a son, but we find no other mention made of him, either in his own writings or elsewhere.