188 HOW TO SEE WITH THE MICROSCOPE. 



chimneys has been a serious objection to its use ; a brand 

 of chimney known in Cleveland as the " Crown" (each 

 chimney having a crown ground in the glass) seem to 

 be very free from breakage. Non-combustible wicks 

 are to be obtained, fitting the K Iceman lamp. These 

 are clean and handy, obviating the necessity of occa- 

 sional cutting and trimming; but to our mind the light 

 is not so intense, and therefore we prefer to use the old 

 style of wick. These lamps burn very steadily, and are 

 not easily affected by occasional drafts, and this is a strong 

 recommendation in their favor, as is also the ease with 

 which they are kept in order. For investigations of 

 exceedingly difficult objects the circular wick is not so 

 well adapted, and recourse must be had to lamps carry- 

 ing flat wicks. The best lamp we know of, of the lat- 

 ter style is the Mechanical Lamp, manufactured in New 

 York City. The lamp stands about ten inches in height. 

 The height cannot be changed, and this is an objection. 

 It burns kerosene oil, without any chimney. The body 

 contains a movement which, on being wound like a clock, 

 drives a blast wheel, and thus supplies a current of air 

 at the point of combustion. Although there is a peri- 

 odicity noticeable in the burning of this lamp, never- 

 theless the flame is very steady, is very intense, and 

 superior to gas. Like the St. Germain, this lamp is 

 very handy to have in the house, and it takes but little 

 trouble to keep it in order. The movement should be 

 cleaned once a year, and any one possessed of fair me- 

 chanical skill will be competent to do this. While 

 burning, the clock-work makes scarcely any noise. An- 



