Proceedings of the Polytechnic Association. 837 



a well, which consisted of a common umbrella inverted and so 

 arranged as to be several times let down to the bottom of the well 

 while closed, and rapidly drawn up while open. The effect was to 

 remove the gas in a few minutes from a well which was so foul as to 

 instantly extinguish a candle previous to the use of the nmbrella. 



Olegeaphs. 

 This name has been applied to the beautiful figures formed when 

 oil is allowed to fall, drop by drop on pure water, which Dr. Carter 

 Moffat has succeeded in fixing on paper. The process consists simply 

 in obtaining the pattern on water, noting the time, laying on the paper 

 glazed side downward, for an instant, and then drawing it through a 

 plate of ink, after which it is washed with water. The method of 

 producing these figures on water was first fully described by Prof. 

 Tomlinson of London, and published last year. 



The Cypress of Somma. 

 This tree in Lombardy, Italy, is said to be the oldest tree in Europe. 

 It is believed to have been in existence at the time of Julius Caesar, 

 forty-two years before Christ, and is therefore 1,911 years old, Na- 

 poleon, when devising his plan for a great road over the-Simplon, 

 diverged from a straight line to avoid injuring this tree. It is 106 

 feet high and twenty feet in circumference, or about one-third the 

 size of the greatest trees in the Calaveras Grove in California. 



Portable Illuminators. 

 M. Alv^ergniat, a French electrician, has made an improvement 

 first suggested to him when using the tubes invented by Giessler, 

 which are cylinders or bulbs (jf glass filled with rarified gas that 

 becomes luminous in the dark when a current of electricity is passed 

 through it. The improvement consists in filling a glass cylinder or 

 or phial, hermetically sealed, with a substance which becomes phos- 

 phorescent by the action of frietional or static electricit_y. A tube of 

 this kind may be of some service to those on night duty, for all that 

 is requisite to produce a feeble and ephemeral light is to rub the tube 

 briskly with a silk handkerchief. 



Temperature of the Blood. 

 Dr. J. S. Lombard has applied his delicate thermo-electric appara- 

 tus to the study of the effects of respiration on the temperature of 



