23 



The liner and finest classes of field instruments, such as those provided with 

 micrometer-microscopes, should always be placed in their boxes for safe conveyance 

 no matter how short the distance for fear of improper handling, and because of 

 danger of unequal expansion, temporary as it may be, of such parts as would come 

 in contact with the body or fingers. 



Carrying an instrument on its tripod without slightly clamping its prin- 

 cipal motions, will wear out the centers. When carrying on its tripod, 



( in TRANSIT, when placed on a line with its centers : 

 clamp telescope j iQ ^^ when hanging down. 



When carrying an instrument in the box it is important that it be placed therein 

 exactly in the position and manner designated by the maker. Therefore, upon re- 

 ceiving a new instrument, the first step should be to study its mode of packing, and 

 if necessary a memorandum should be made for future guidance and pasted in the 

 box. This will save time and vexation, as some of the boxes for field instruments 

 must necessarily be crowded to be light and portable. 



Before placing an instrument with four leveling screws in its box, the foot-plate 

 should be made parallel to the instrument proper, and then brought to a firm 

 bearing by the leveling screws. The instrument must also be well screwed to the 

 slide-board, if one is provided, as is the case in most of our transits. Having put 

 the instrument in the box in such a position, that no part of it will touch the sides, 

 the principal motions are now to be checked by the clamp screws, to prevent mo- 

 tion and striking against the box, Wiia instruments not standing erect in their 

 boxes, but which are laid on their sides in resting-places, padded with cloth, speci- 

 ally provided for that purpose, their principal motions must not be clamped until 

 the instrument has been secured in a complete state of repose in these receptacles, 

 so as to be entirely free from any strain. Care must be taken, too, that all of the 

 detached parts of an instrument, as well as its accessories, are properly secured 

 to their receptacles before shutting the box. 



When shipping an instrument over a long distance it is commendable to fill the 

 hollow space between it and its box with small soft cushions made of paper, or of 

 excelsior or shavings wrapped in soft paper, taking care not to scratch the metal 

 surfaces, nor to bend exposed parts, nor to press against any adjusting screws. 



For greater safety in transportation by express, the instrument-box itself should 

 always be packed in a pine- wood box one inch larger all around. For the ordinary 

 size of field instrument the packing-case should be provided with a strong rope 

 handle, which, like the strap of the instrument box, should pass over the top of the 

 case and through holes in the sides, the knots being within the case and strongly 

 secured. In cases where the gross weight of the entire package, as prepared for 

 shipment in the above manner, exceeds 40 or 50 Ibs., then two men should handle it, 

 and two strong rope handles, one at each end of the packing-case, should be provi- 

 ded. In order to check jars and vibrations while en route, the loose space between 

 the instrument-box and the packing-case is to be filled with dry and loose shavings. 



The cover bearing the directions should always be screwed on and marked thus, 

 in large black letters : 



THIS SIDE UP. 



HANDLE WITH GREAT 



Scientific Instrument. 



Mr. George Brown, 



36 West Street, 

 Value S Cleveland, 



Ohio. 



From JOHX SMITH, Chicago, Illinois. 



