19 



THIRD ANNUAL JOINT MEETING OF THE CORNISH 

 SCIENTIFIC SOCIETIES. 



The Scientific Societies of Cornwall — The Eoyal G-eological 

 Society of Cornwall, The Eoyal Institution of Cornwall, The 

 Eoyal Cornwall Polytechnic Society, and The Mining Association 

 and Institute of Cornwall, — held their annual joint meeting on 

 Tuesday, July 16th, 1895. The principal item in the day's 

 programme was a rock-drilling demonstration at Wheal Agar 

 mine. This was arranged by the Tuckingmill Foundry Company, 

 who have recently erected at Wheal Agar a splendid specimen 

 of Mr. McCulloch's new compound air-compressor, of which 

 some interesting particulars will be found in a later portion of 

 this report. The Foundry Company are the makers not only of 

 this engine, but of the " Eio Tinto " and "Little Hercules" 

 rock drills, of which Mr. McCuUoch is also the inventor and 

 patentee. The " Eio Tinto " is a drill of world-wide fame, 

 having come out of many important competitions with flying 

 colours. The "Little Hercules," a more recent invention, is 

 claimed by Mr. McCuUoch to represent a great improvement on 

 the " Rio Tinto." It is much lighter and shorter, and to show 

 that it combines with these advantages the still greater advantage 

 of increased speed capacity, was the principal object of the 

 demonstration which took place on Tuesday. A large company 

 assembled at Wheal Agar, and watched the proceedings with 

 the greatest possible interest. The drills were tested on large 

 blocks of the hardest granite, and were worked at an air pressure 

 of seventy pounds to the square inch. Mr. William Thomas, 

 secretary of the Mining Association and Institute, acted as 

 adjudicator, and the results as given by him were as follow : — 

 In the first case the " Hio Tinto " bored five inches in a minute ; 

 whilst " TheLittle Hercules" bored 12:^ inches in 57 seconds, 

 each with a 1^ inch bit. A horizontal hole, five feet four and a 

 half inches long, was next bored by "The Little Hercules" in 

 eight minutes fifty three seconds. The time occupied in this trial 

 from start to finish, including stoppages, was 18 minutes, and 

 the bits varied from 2^ inches down to 1^ inches. In the next 



