368 THE AMERICAN MONTHLY [Nov. 



The mechanical stage is operated by the small chains 

 which extend along the sides of the frame of the appa- 

 ratus, and the rotation of the objective, polariscope, etc., 

 and the focusing are effected by rods extended toward 

 the rear of the camera box. With these adjustments the 

 operator seated at the camera can manipulate the instru- 

 ment for focusing or searching the field for any partic- 

 ular object. 



The instrument has been used for making negatives 

 showing objects with a magnification of 15,000 times. 

 All the parts are made adjustable for wear and atmos- 

 pheric changes and for adaptation to various classes of 

 work. 



This photomicrographic apparatus forms an important 

 part of the equipment of the laboratory of microscopy 

 of Bellevue Hospital, 



Address of Welcome to the American Microscopical Society 



Upon its Assembling in Carnegie Library Pittsburg, 



Pa., August i8. i8q6. 



By Rev. W. J. HOLLAND. 

 Chancellor of the "Western University of Pa. 



PITTSBURG, PA. 



It is a very great pleasure to me on behalf of the local 

 scientific societies and the citizens of this town to extend 

 to you on this occasion a most cordial welcome. Hospi- 

 tality, as you all know, is an ancient grace and virtue, 

 and I have heard it said by Pittsburgers that they excel 

 in this virtue, and I, in fact, have heard others that have 

 been in Pittsburg venture to intimate thatthe claimis just. 

 There have been some historic interruptions to the hos- 

 pitalities shown by Pittsburgers, notably when General 

 Braddock kept the Indians on the other side of the Mo- 

 nongahela River during the French and Indian War. 



