TEANSACTIOXS OF SECTION A. 37 



an alternate-current clynaino working at a tension of about 

 400 volts, and a transformer by means of which the current 

 from the dynamo is reduced to one of enormous value at very 

 low pressure. This transformation is necessary, as heating 

 effect is proportional to the square of current strength. 



The terminals of the large current circuit are two massive 

 clamps, one of which is fixed while the other can move to and 

 fro. The latter is provided with a powerful screw used for 

 applying end pressure to the weld. 



When two pieces of bar are to be joined their ends are 

 prepared, and they are then placed in the clamp with the pre- 

 pared ends in contact. The current is turned on, the junction 

 soon becomes white-hot, all the other parts of the bar remain- 

 ing cool, pressure is applied by the screw, and the thing is 

 done. 



The beauty of the process from a scientific point of view is 

 the fact that in it almost all the energy required, either as heat 

 or wofk, is given to the place where it is required, and to 

 nowhere else, so that extremely little is lost. 



The number of industries to which this art has already been 

 applied is enormous, and it is impossible to foresee by how 

 much the number of its applications may be increased. 



I must now conclude. I hope that the few examples of the 

 late advances in science have sufficiently interested you. Many 

 others I might have spoken of, but I think I have said enough 

 to convince you that the last decade has been one of very great 

 scientific activitv. 



1. TJie Earthquakes of New Zealand. ^ 



By George Hogben, M.A., Timaru, New Zealand. 

 Plate III. 



This paper is founded upon the records of 775 earthquake- 

 shocks felt in New Zealand, between the years 1848 and 1890, 

 inclusive. These records have been obtained by a systematic 

 search of some of the leading journals, from the list and notes 

 thereon published annually in the x\ppendix to the " Trans- 

 actions of the New Zealand Institute," from private sources, 

 and, since December, 1889, by means of notices forwarded by 

 officers of the Telegraph Department from stations in various 

 parts of the colony. 



The records are incomplete in the following respects : — 

 (1.) They do not include all existing records : the systema- 

 tic search of the newspapers of past years has not been 

 completed yet ; and many valuable private records of whose 



