Proceedings of the Polytechnic Association. 751 



ber of Ijoxes with the number of every room and the name of each 

 occupant, placed on the outside, each box having a lock and key. The 

 apparatus being placed at the entrance to the building, the letter car- 

 rier can at once see the box in which to j^lace the letter. 



New Traveler's Trunk. 



Mr. Hudson exhibited a trunk, the covering of wiiich was made of 

 slats of hard Avood, riveted transeversely to the pine wood of the box. 

 This plan increases the strength of the trunk very much. The usual 

 covering of leather hardly giving any strength at all. The trunk was 

 a well finished specimen of the kind. It weighed about the same, 

 and the cost is equal to the leather trunk. One of tliis kind would 

 be thirty -five dollars. 



Dr. J. B. Rich remarked that canvas saturated with linseed oil was 

 a much better covering for trunks than leather, that is, if the duck or 

 canvas is thoroughly saturated. It is far superior ,to sole leather, as 

 it will not stain witli grease. In iegard to the strength of trunks, he 

 had lately witnessed some experiments with them. He saw a trunk 

 having India rubber placed on the corners, which was filled with 

 books, and thrown down a distance of twenty feet, and yet it did not 

 sustain any damage. These trunks are manufactured by J. C. Gil- 

 more. 



Mr. Newberry tliought that saturating the canvas with oil would 

 decompose the canvas. 



Steel Plated Cast Iron Axes. 

 Dr. W. RoM^ell exhibited some cast iron axes, plated with steel. 

 The steel facing is struck up with a die, and the cast iron, in a mol- 

 ten state poured on it ; a perfect union of the steel and iron is thus 

 efi'ected. The price of the axes is about half that of cast steel. Mr. 

 Meigs, of East Berlin, Conn,, is the inventor. The steel being laid 

 in the sand and the cast iron poured on it, tliere is no waste of the 

 steel, and a thorough weld of the steel produced. 



Steel Bridle Bits. 

 Dr. Rowell also showed some cast steel bits, made by Mr. B, T. 

 Henry, of New Haven, Conn. The rings of the bits are made of 

 steel wire and the ends are melted toerether with the flame ffoin^ 

 through perforated brick, and when at a welding heat the ends are 

 squeezed together, which makes a perfect weld, requiring no after 

 finishing. 



