126 KANSAS CITY REVIEW OF SCIENCE. 



sixty tons per square foot, and again taking one-sixth as a factor of safety, we will 

 have ten tons per square foot as the safe load, and if each pier has four and one- 

 half square feet, it will give forty-five tons as the safe load to be imposed upon 

 piers of this size. 



It will be seen from this that the load of 189 tons was four and one-quarter 

 times as great as the pier was reasonably able to carry. It is therefore evident 

 that the brick piers, being the weakest part of the structure, had to give way first, 

 and they caused the disaster. 



While the above calculations are based upon brick piers of the very best 

 quahty of workmanship and materials, the piers in this building were not a fair 

 average of work. 



The side walls of the building are of the regular thickness, and strong 

 enough for all practical purposes. The workmanship and material are of average 

 quality. 



(Signed), Charles R. Ramsey, 



Thomas B. Aman, 

 F. W. Raeder. 



THE LAY TORPEDO. 



The most successful type of the moveable torpedo is found in the invention 

 of Mr. John L. Lay, of Buffalo, New York, who has heretofore been mentioned 

 as associated with Chief-Engineer Wood in the invention of the torpedo used by 

 Cushing. As excellent as the Lay undoubtedly is, it still has the same defect as 

 others, namely, want of sufficient speed ; this, however, does not seem to be an 

 insuperable obstacle, and with each successive construction a greater speed is 

 obtained. The boat is always under the control of the operator, who can stop or 

 start it, steer to either one side or the other or fire the charge whenever he pleas- 

 es. All these things are of course extremely advantageous, and greatly enhance 

 the value of the weapon. The motive power is carbonic acid gas. This gas (as 

 is well known) becomes liquified under a pressure of forty atmospheres, and in 

 this state it is stored in a flask in the boat. When the valve closing this flask is 

 open, vaporization ensues, and the gas is taken to the engine, first passing an 

 automatically acting reducing valve, so that the pressure will not be too great. 

 As the liquid expands, great cold is produced, and trouble is experienced from 

 its use as a motor ; this, however, is not a serious difficulty, and remedy will 

 doubtless be found. The explosive chamber, containing five hundred pounds of 

 material, is at the bow, and is so constructed that on contact with a vessel it is 

 disengaged from its resting-place, and drops several feet, the idea being that an 

 explosion in that position will do more damage than at the water-line. In one 

 compartment of the boat is a drum, from which is paid out the cable through 

 which the electric current passes. A suitable arrangement of magnets opens a 

 valve which allows gas to enter a cyHnder, the piston in which causes the helm 



