■604 PROCEEDINGS OF SECTION H. 



formed of a combination of hollow spheres, each Sin. in diameter 

 externally and fin. thick, connected by cm-ved necks 3jin. diameter. 

 These spheres are held toijether by Avrought-iron bolts, and in one 

 ■direction are cast in sets of two or four with opposite lateral open- 

 ings to each sphere, called by the inventor two or four balled 

 •elements, as the case may be. He assumes that the boiler, in its 

 smallest form, may be considered as one of these balls with its 

 opposite lateral openings closed by caps held in place by bolts. 

 Two balls united by a neck with caps over the four lateral openings 

 would make a boiler of the next larger size," &c. ..." Any 

 number of these balls or spheres may be united by bolts passing 

 through them, so as to form large boilers. The strength of these 

 boilers will be that of the weakest sphere in the structure. In 

 manufacturing the boiler for ordinary use a number of these ele- 

 ments are so arranged as to form sections twelve balls long, six 

 balls wide. These sections are all tested by hydraulic pressure as 

 liigh as SOOlbs. per square inch before being delivered to purchasers. 

 The committee saw one of these sections subjected to a biu'sting 

 pressure of water, one sphere bursting when the pressure reached 

 ■GOOlbs. per square inch. They were shown a section in which one 

 unit had burst at 900lbs. per square irsch ; the damage was repaired 

 by the insertion of a riew unit. The section then stood l,100lbs. 

 per square inch before bursting in a new place. The available 

 strength of the section in all cases being the strength of the weakest 

 unit in it. the inventor holds that it is safer than any other in use," 



&c " To prove which he had a section equal to six 



horsepower, similar to the one tested by hydraulic pressure and 

 such as he is regularly selling, placed in an extemporary furnace 

 Tjuilt in a clay bank and set in the usvial manner for a boder oi this 

 kind. The boiler was filled with water to the usual height— about 

 two thirds full^and with no outlet or safety valve of any land, 

 sealed up tight, a small tube leading from the upper ball to a high- 

 pressure gauge placed at a safe distance, about '2uOft., from the 

 toiler; a fire was made under and around the boiler with dry fire- 

 wood. The wind was very high at the time, blowing directly unto 

 the furnace, thus fanning the flames to an intense heat. The pres- 

 sure increased at a uniform rate until it had leached the enormous 

 strain of SoOlbs. per square inch, when a sudden discharge of 

 steam took [dace, seemingly no greater in volume than might issue 

 from a safety valve of 2|^in. diameter, after which the pressure fell 

 to 45()lbs., at which it stood until the fire was drawn." 



'•November 13th, 1866 — At 4 o'clock the committee met at 

 the factory," and it was found that some bolts "had become 

 slack." 



This statement is taken from the " Journal " of the Franklin 

 Institute, February, 1867. The "Journal" seems sober enough. 

 Unluckily no particulars are given of how the pressure gauge was 

 tested, and the committee seem to have failed to make the most of 



