or correspondents of the Institution in their respective countries. Be- 

 yond this there is no expense to the sender. 



A scientific society or an individual in the United States desiring 

 to take advantage of the Exchange vSer\'ice should have all packages 

 strongly wrapped and legibly and fully addressed. All packages con- 

 stituting a consignment should be carefully packed to avoid being 

 damaged in transit, and forwarded to the Smithsonian Institution at 

 Washington, carriage prepaid. The .separate packages should not 

 exceed one-half of one cubic foot in bulk, and they should not contain 

 letters or other written matter. 



In forwarding exchanges the sender should address a letter to the 

 Institution, stating by what route the consignment is being shipped to 

 Washington, and the number of boxes or parcels of which it is composed. 



On the receipt of a consignment at the Institution each package is 

 as,signed an "invoice number," and a record is made of the entire 

 list of packages under the sender's name. The separate packages are 

 also entered under the name of the person or office addressed. An 

 account is thus established with every correspondent of the Institution, 

 which shows readily what packages each one has sent or received 

 through the Exchange Service. The books are then packed in boxes 

 with contributions from other senders for the same country, and are 

 forwarded by fast freight to the bureau or agency abroad which has un- 

 dertaken to distribute exchanges in that country. To Great Britain 

 and Germany, where paid agencies of the In.stitution are maiiitained, 

 shipments are made weekly ; to other countries they are made at some- 

 what greater intervals. 



Each package sent out contains an addressed receipt card bearing an 

 ' ' invoice number ' ' identical with that upon the package. This invoice 

 number should be carefully noted by the recipient, as it is the iiwaiis 

 of identifying l/ic pac/cai^r, and it is important that the card should be 

 signed and mailed to the Institution without delay. The receipt having 

 been filed in the Exchange Office, the record of that particular package 

 . is made complete, while failure to return the receipt card gives rise to 

 doubt as to the correctness of the address, and future packages for 

 that address may be returned to the sender. 



Transmissions from abroad are received by freight in large boxes, 

 and are distributed in the United States under frank by registered mail, 

 a record first having been made of the name of the .sender and of the 

 address of each package. A receipt card, returnable b}- mail without 

 po.stage, is sent with each of these packages, and the recipient should 

 sign and return it to the Institution at once as an acknowledgment of 

 the package. 



The Institution and its agents will not knowingly receive for any 

 address purchased books, nor apparatus or instruments of any descrip- 



