This database and its documentation are ©2001-2007 Adler Planetarium & Astronomy Museum.

The database is made freely available for scholarly use, but it is not in the public domain. You may copy or redistribute the database in any form, but you may not charge money for it except to recover your expenses.

No warranty of any kind is associated with the database.

This database of instrument makers, or more precisely of their signatures, is a product of many years of research by Roderick and Marjorie Webster, longtime curators of the collection of scientific instruments at Chicago's Adler Planetarium & Astronomy Museum.

The Adler has the finest such collection in the western hemisphere, but when the Websters arrived in the early 1960s as volunteer curators the Adler collection had long been neglected. They quickly took up the serious study of scientific instruments, traveling widely to study and photograph instruments in other collections. In their travels the Websters took copious notes about the instrument makers whose work they encountered.

Realizing early the benefits of computerization, they acquired a Vector Graphics microcomputer and commissioned a custom database into which they could enter the information and notes they had accumulated on instrument makers. This custom database was later converted to the MS-DOS operating system, and was updated in that form until Rod Webster's death in 1997. In 2001 Madge Webster formally gave the database to the Adler Planetarium.

Data have been extracted from the custom database by Bill Burns (ftldesign.com), who is in no way responsible for any errors that exist in the data. We are grateful for his generous assistance. This project seems to us an example of the merits of distributing free (to you) or low-cost (to us) information on the Web.

The presentation of these data could be improved in many ways, mostly involving money or time which is not available. Take this for what it is: a work in progress and a guide to research, rather than an authoritative reference. We welcome additions or corrections, which may be submitted directly from Database Search Form.

Enter the signature in which you are interested into the Search for box and click the Search button. Once you are familiar with the database, you can search fields other than the Signature by checking and unchecking boxes to the left of the field names.

To suggest a correction to the database, click Suggest a Correction at the top of the Search Results page. A Suggest Correction column appears with a clickable field for each row in the results. Click that field for the entry you wish to correct to enter Correction mode. The database will present that entry, followed by an editable duplicate entry. Make your changes in the duplicate entry and click Suggest correction.

A curator will review your suggestion and may correct the database. If you provide an e-mail address at the bottom of the form, the curator will be able to contact you for further information about your suggested correction.

1. The literal signature, possibly with an appended number. A single signature used by several instrument makers is listed several times with sequential numbers appended. Appended sequence numbers are not part of the signature.

2. Information-not guaranteed-about the instrument maker. This may include nationality, dates, and an abbreviation indicating the types of instruments on which the signature sppears.

3. A list of instruments known to be attributed to the instrument maker, with the location or institution at which they were observed. A table of abbreviations used for instrument locations is linked to the main database page.

4. Comments can be almost anything.

5. Location or address at which the instrument maker worked. Often unknown; sometimes a city; sometimes a street address or list of addresses.

6. References.