Russegger's Betnarks on the Climate of Eg if pt. 03 



Hud subsequent ignition of its carbon. Pure hydrogen, when burned, 

 Affords a very feeble light ; and whenever so much air is mixed with coal- 

 gas as is sufficient to consume all its carbon simultaneously with its hy- 

 drogen, it bums with a dim blue flame. Now, in the base of a common 

 argand flame, an excess of cold atmospheric oxygen is allowed to act 

 upon the coal gas in the vacant spaces between the pin-holes, whereby 

 the temperature being greatly lowered, while the carbon is consumed in 

 the gaseous state, the light from these two causes is nearly null. It is 

 not till the gaseous mixture rises and forms a continuous hot cylinder, 

 without interstitial streams of air, that it emits a white light from the 

 ignited particles of the carbon precipitated in the interior of the flame. 



In Mr Gurney's concentric series, the prejudicial excess of atmospheric 

 air is prevented, and only so much permitted to come into contact with 

 the gas, as will effect the due separation and ignition of its carbon, even 

 at the origin of the flame. 



To these two causes conjoined, viz. the increased intensity of ignition, 

 and the limited supply of oxygen, it is that the new Bude flame owes its 

 economy of illumination. The effect of oxygen in excess, is elegantly 

 demonstrated by throwing up a stream of it within a gas argand flame, 

 for the light is thus nearly annihilated, while the heat is prodigiously 

 ftugmented. 



As regards the specification of the patent for this improved mode of light- 

 ing, which I have carefully examined, I have no hesitation in declaring it, 

 in my opinion, to be valid and unimpeachable. — The London Journal 

 and Repertory of Arts, Sciences, and Manufactures, No. CXXV.^ p. 292. 



Remarks ott the Climate of Egypt. By M. Joseph Russeggeh, 

 Austrian Councillor of Mines. 



Seasons. — Lower Egypt, lying between the 3()th and 31st 

 degrees of latitude, belongs, in so far as regards the yearly 

 periodical sequence of the seasons, to the system of Southern 

 Europe, but of course presents those modifications which are 

 peculiar to warmer climates. Thus, Lower Egypt has its 

 summer and its winter at the time of our own, only with this 

 difference, that the latter is a period of rain, which occurs 

 during our winter months. Spring and autumn almost entirely 

 disappear in warm climates, and there those delightful tran- 

 sitions from winter to summer, and vice versa, which we enjoy 

 in the more temperate zones, are unknown. In tropical coim- 

 tries there is nothing but summer, viz. a summer which ia 

 entirely dry, and one during which it rains more or less. 

 These rains continue there during half the year ; whereas in 

 Egypt, as in a northern winter, they are confined to a few 

 months. Of course they do not give rise to tluit winter-slee[> 



