THE MICROSCOPE. 239 



OUR ADVERTISERS. 



We wish it distinctly understood that we never use our influence 

 forany particular dealer in microscopes who advertises in this jour- 

 nal. Yet we stand ready at all times to give advice to any sub- 

 scriber who may wish to purchase goods. The plan they must in- 

 variably follow is this: Send to the various firms advertised in our 

 pages for circulars of the goods you wish. Peruse these circulars 

 carefully, and make up your mind of what firm you intend to pur- 

 chase, then we will step in and assist you in any way. In no case 

 will we decide the house for you. Our answer will invariably be that 

 each house represented with us is responsible and will carry out all 

 they agree to do. So please cease writing such foolish questions: 

 "Which house is the best?" "Are they all honest?" 



Bausch & Lomb have just completed a new pattern for their 

 investigator, called "The Investigator Improved." The course 

 adjustment of the "improved" moves nearly two inches higher. 

 The pillar is heavier and higher and has separable swinging sub- 

 stage and mirror bars, each graduated. They have just completed 

 a new % objective of 75 ° with an extra large working distance. It 

 easily resolves the p. angulatum by central light and yet has an 

 unusually large working distance. It will have a large sale for pur- 

 poses of urinalysis. 



We did not mean any injustice to the house of R. and J. Beck, 

 when we mentioned some months ago that we regretted the slight 

 advance they had made in the price of some of their goods. 

 The advance was not general but applied only to a few special 

 stands. Their "Scholar's" microscope at $25.00 must be sold with- 

 out profit certainly. Dr. Donelson, of Muskegon, Mich., has just 

 supplied himself with one of their "New National Improved," com- 

 plete. He is delighted with it. The "Ideal" is as popular as ever 

 with working microscopists. 



Chas. Fasoldt, of Albany, recently sent us a micrometer 

 which showed the so-called "rings of Newton" in a beautiful 

 manner. He mailed at the same time a newly ruled micrometer, 

 each alternate line being ruled longer, so that the end of each band 

 is half the value of the band proper; that is, if the band was in the 

 field ruled 50,000 to the inch, then the end of that band would show 

 25,000 to the inch. Therefore, as Mr. Fasoldt says, "one can easily 

 judge if there is any diffraction." 



We have just received from The Prang Educational Com- 

 pany, one of the camera lucidas of Oberhauser, which they offer for 

 $16. The ease with which this camera can be used, together with 

 the perfect image that it gives, make it a very desirable acces- 

 sory. So far as we- know it is the only house in this country that 

 deals with the justly celebrated microscopes and objectives of' Hart- 

 nack. By the way, Harvard College men use no other make. 



