-n 



The Finish. 



It is a well-known fact that the black finish has one objection. It absorbs the 

 heat readily, and therefore is apt to expand an instrument unequally, and thereby 

 deranges its adjustments. We therefore consider it necessary to finish certain parts 

 of an instrument in a bright but not glaring finish including the upper plate, the 

 standards and the telescope in the transit; the cross-bar and the telescope in the 

 wye level, etc. All other portions may be finished and bronzed before lacquering. 

 This finish gives a very fine appearance to the whole instrument ; it wears better 

 than black, and is in better taste. 



Customers desiring to have their instruments finished entirely in bronze, how- 

 ever, can do so by notifying us of their wishes. 



Cloth Finish. 



Sometimes Called Asbestos Finish from tlie fact that Asbestos is used 

 in Connection with it. 



It is so called because the parts of an instrument so finished have the feeling to 

 the hand of being covered with cloth of a very close texture, there is no further 

 resemblance to cloth however. 



The principle is borrowed from astronomical instruments, where it is necessary 

 to cover the surfaces with some non-conducting material in order to avoid disturb- 

 ances in instrumental adjustments caused by suddenly varying temperatures. 



We have adopted this principle with the view of securing the same results for 

 our finer transits, wye and dumpy levels. Some of these levels are sensitive to a 

 depression of a single second of arc. 



Instruments finished in this manner heat up or cool down very gradually, 

 causing the minimum derangement of the adjustments, and being of a dark brown 

 color, this finish unites all the advantages of a bright finish with the convenience 

 of having a dark colored instrument to use in the sunshine. 



As regards durability, it will not quite equal the bright finish, but is superior to 

 the bronze or black ; this fact, coupled with the ease with which it can be restored 

 at any time, leads us to recommend it in all cases where engineers do not care so 

 much for an elegant appearing instrument after a number of years, as for an 

 instrument in which every precaution is taken to avoid the influence of sudden 

 changes of temperature. 



In finishing an instrument in this manner, we are not obliged to polish its 

 surfaces so finely, and thus can offer our transits with standards finished in this 

 manner at $5 less than when finished in the other ways. 



Packing. 



In putting our instruments in their cases, none of them separate above the leveling 

 screws. They stand erect, and are ready for use upon unlocking the case. 



The cases are provided with rubber cushions, to check severe jarring arising from 

 transportation over rough roads. 



In conclusion, we wish to say that we aim to secure in our engineers' 

 Instruments 



1. Simplicity in manipulation. 



2. Lightness, combined with strength. 



3. Accuracy of division. 



4. Achromatic telescope, with high power. 



5. Steadiness of adjustments under varying temperatures. 



6. Stiffness ; to avoid any tremor even in a strong wind. 



And we would add, that since all our leveling, tangent and gradienter screws 

 are cut with precision in our engine lathes, and then run through a size plate to 

 ensure uniformity and perfect smoothness, that we are able to replace any such 

 part of our instruments by mail. The spiral springs, and most other small parU 

 of the instrument, can be supplied in the same manner. 



