March 27, 1902] 



NA TURE 



49. S 



Fayum depression have led to the discovery of several 

 new creatures. "The most important of these," he says, 



Fig. I. — Arsinoitherinm Zitteti. Beidn. Si:!e V 



" is a large, heavily built, ungulate, about the size of a 

 rhinoceros, and for which the writer proposes the generic 



being A. Zitteli, in honour of the eminent geologist, who 

 may be regarded as the pioneer of geology in Egypt, and 

 whose work when attached to the Rohlfs Expedition of 

 ■S73-74 is well known to all geologists." The accom- 

 panying illustrations, reproduced from the paper, show 

 a side view (Fig. i) and a back view (Fig. 2) of the type 

 specimen. 



name Arsinoitherinm, from Queen Arsinoe, after whom 

 the Fayum was called in Ptolemaic times, the species 



NO. I 69 I, VOL. 65] 



BR YAN [DONKIN. 



BY the death of Mr. Bryan Donkin at Brussels on 

 March 4 the engineering profession has lost one 

 of its members who devoted himself with more than 

 ordinary assiduity to the scientific side of his calling. The 

 name of Bryan Donkin was eminent in the world of 

 mechanical engineering for the whole of the last century. 

 The late Mr. Donkm succeeded, in due course, to the 

 management of the business which his grandfather, the 

 first Bryan Donkin, had founded in 1S03 for the manu- 

 facture of paper-making machinery ; a new process for 

 producing continuous rolls having been then recently 

 introduced. Bryan Donkin, jun., as the subject of our 

 memoir was known until quite recent times, was born in 

 1835, and was educated at University College, London, 

 and at the Ecole Centrale des Arts et Metiers in Paris, 

 where he was for two years. After that he was appren- 

 ticed to his uncle at the Bermondsey works, his father, 

 John Donkin, having died at a comparatively early age. 

 In 1859 he went to St. Petersburg to superintend the 

 erection of a large paper mill which was being established 

 under the Imperial Russian Government for the manu- 

 facture of bank notes and State papers. He returned 

 to this country and in 186S became a partner in the 

 Bermondsey firm. In 1889 the business was turned into 

 a limited company, of which Mr. Donkin was chairman. 



It was not, however, as the head of a manufacturing 

 business that Mr. Bryan Donkin was best known in 

 engineering circles, but as an experimenter and a student 

 in thermodynamics and a reader of papers before 

 technical societies. His first important work was under- 

 taken in conjunction with Mr. Farey, who was also a 

 partner in the Bermondsey firm. The latter had invented 

 a steam-engine, which was known by his name, and it 

 was determined that a complete test should be made to 

 ascertain its efficiency. One of these engines had been 

 erected to drive a paper mill in Devonshire, and the 

 method of testing by measuring the heat discharged with 

 the condensing water was adopted. The principles then 

 followed are now well known, but thirty years ago scientific 

 testing was a very rare thing among engine makers. The 

 temperature of the water was naturally not difficult to 

 ascertain, but to measure the volume with accuracy 

 was a formidable task. How this was done by means of 

 the notched weir and the application of a simple hydraulic 

 law is too familiar to all engineers to need describing 

 afresh. 



Mr. Donkin carried on an extensive correspondence 

 with continental engineers ; probably he was more closely 

 in touch with foreign scientific experts in the field of 

 steam engineering than any of his compatriots. He 

 devoted a great -deal of attention to the use of super- 

 heated steam, and in the course of some experiments 

 he devised an instrument he designated the " steam 

 revealer." It consisted essentially of a glass vessel into 

 which steam from the engine cylinder was admitted. By 

 observing whether the steam was transparent or was 

 clouded by the presence of watery vapour, it was possible 

 to estimate if the steam were either superheated or satu- 

 rated, or whether liquefaction had set in. A paper on 

 this subject was read by its inventor before the Institu- 

 tion of Mechanical Engineers in October, igoo. Of late 

 years Mr. Donkin devoted a good deal of attention to 

 internal combustion motors. A book on " The Gas 



