348 JOSEPH TTIKLOCK. 



Donati's comet of 1858, and Coggia's comet of 1874, in some of their 

 wonderful transformations. 



In August, 1874, Mr. Wiulock was appointed by Secretary Bristow 

 chairman of the commission established by Act of Congress for making 

 inquiries into the causes of steam-boiler explosions. He entered into 

 this investigation with remarkable energy; carefully analyzed the 

 various theories which had been suggested to explain this class of 

 accidents ; and ended with devising a number of ingenious experi- 

 ments calculated either to confirm or refute them in detail. The 

 arrangements were nearly completed for making these experiments 

 at Sandy Hook and at Pittsburgh, when death put an end to his 

 labors. 



In the early part of his active career, Mr. Winlock was known and 

 trusted as an accomplished teacher and an excellent mathematician ; 

 well versed in theoretical astronomy, and capable of applying it in 

 laborious and responsible calculations. These qualifications pointed 

 him out as a proper person to be made director of an observatory. 

 With his new opportunity, he developed other talents, which, if not 

 indispensable, were none the less valuable in his changed condition. 

 It might have been expected that his clear mathematical mind would 

 easily comprehend the ph3^sics and the geometry' of the instruments 

 whose usefulness he was to guide, and seize upon any defects which 

 might exist in their construction. In devising remedies for these 

 defects, as simple as they were sufficient, he displayed an originality in 

 his mechanical ideas, and a spirit of invention, which left nothing 

 wanting to fill out the measure of a consummate director. Without 

 any passion for innovation, or any conceit of his own methods, he was 

 not afraid to leave an easy and well-worn path, or disturb the most 

 time-hallowed routine, if he could give good reasons for the change. 

 The life of an assistant at an observatory, obliged to work while other 

 men sleep, exposed to the caprices of the clouds, made nervous by the 

 irregularity of his hours, the nice handling of his instruments, and the 

 delicacy of the work expeoi^ed of him ; disappointed at the critical 

 moment in realizing the fruits of anxious days of preparation, — such a 

 life is dependent, in no small degree, not only for its happiness, but its 

 endurance even, upon innumerable and indescribable little facilities for 

 observation, which individually are not worth the mention, but which 

 in the aggregate tell distinctly upon the success and the comfort of the 

 profession. In his many innovations, of which every room and each 

 instrument in the Observatcny is a witness, ]\h'. Winlock was not 

 misled by any theoretical abstractions, but moved always within the 

 limits of practical good sense. 



