Proceedings of the P olytechnic Association. gl7 



Tea Float. 



Messrs. Field, of Neweastle-upoii-tlie-Tine, have devised and pat- 

 ented a method of making tea, which they claim effects a saving in 

 the amount of the tea used. Boiling tea has a tendency to dissipate 

 tlie active principle, theine, but exposing the leaves to the highest 

 temperature belowthe boiling point extracts the theine rapidly, with- 

 out making the beverage unpalatable. As the hottest portion of the 

 water is always at the' top of the vessel, the tea is j)laced in a cylindri- 

 cal metallic sieve, which is mad« to float by means of an air chamber 

 attached to it, so that the tea is always in the position to be influenced 

 by the greatest heat. 



Bottom-Cast Steel Ingots. 

 Mr-. A. L. Holly, of the Pennsylvania Steel Works has introduced 

 a new process in casting Bessemer steel ingots, which consists- of 

 making a nest of ingots in one piece by pouring the metal at the 

 bottom and in the center of the mold. In this manner 5,000 ino'ots^ 

 have been cast^ mostly in groups of seven. Arrangements are now 

 being made to cast the whole charge of five tons in a group of thirteen. 

 The improved flasks- consist of large cast iron bottoms, with a central 

 cavity, in wliich the prolongation of the central or spnie mold is 

 formed, and radical •channels in which the runners from this sprue 

 mold to tlie surrounding molds are formed. The cavity and runners 

 are lined with molding material (old ground fire-brick and loam) from* 

 one-half to one inch in thickness. The patterns are all formed on the 

 follow-board, and drawn at one opei'ation. The advantages of Mr. 

 Holley's process over the ordinary one of j^ouring into the top of 

 the mold are : 



1. The improved quality of the ingots. In the- ordinary method 

 the steel falls the whole length of the mold and spatters on tlie sides^ 

 consequently the ingot is more or less porous. By the new plan the' 

 steel rises gradually in the mold, and is pressed against the top by a 

 ferro-static column, one foot or more in height. The ingot thus made- 

 is less porous, and has a smooth exterior. 



2. A saving of scrap ; for under the old system the ingots caflnot, 

 be made of uniform length. 



3. Convenience of working ; the best proof of it being that the 

 workmen prefer the new process. 



4. The saving of the ingot molds. Many of the molds of the 

 new model in the Pennsylvania Steel Works have been used. 4iOQ/ 



[Inst.] 52 



