Een archieftoegang geeft uitgebreide informatie over een bepaald archief.
Een archieftoegang bestaat over het algemeen uit de navolgende onderdelen:
• Kenmerken van het archief
• Inleiding op het archief
• Inventaris of plaatsingslijst
• Eventueel bijlagen
De kenmerken van het archief zijn o.m. de omvang, vindplaats, beschikbaarheid, openbaarheid en andere.
De inleiding op het archief bevat interessante informatie over de geschiedenis van het archief, achtergronden van de archiefvormer en kan ook aanwijzingen voor het gebruik bevatten.
De inventaris of plaatsingslijst is een hiërarchisch opgebouwd overzicht van beschreven archiefstukken. De beschrijvingen zijn formeel en globaal. Het lezen en begrijpen van een inventaris behoeft enige oefening en ervaring.
Bij het zoeken in de inventaris wordt de hiërarchie gevolgd. De rubrieken in de inventaris maken deel uit van de beschrijving op een lager niveau. Komt de zoekterm in een hoger niveau voor, dan voldoen onderliggende niveaus ook aan de zoekvraag.
3. History, scope and contents of the Pieter Zeeman papers
The oldest documents in the Pieter Zeeman papers date from around 1877 (inv.nrs. 242-243). When he moved to Delft in 1882 to prepare for his supplementary examination in Latin and Greek, his parents began a regular correspondence with him. From this period also remain some notes and notebooks. When he moved to Leiden in 1885, the correspondence with his parents continued. In addition, many of his student notebooks, his research notes and notebooks and many other documents relating to his physics studies and personal life during this period were preserved.
Around 1895, Zeeman established a pattern regarding his personal papers which continued until his death. Perhaps his marriage in that year and the administration of his wife's considerable fortune, which it entailed, convinced him of the benefits of systematic record keeping.
Zeeman began to collect his letters in binders, 57 in all, divided by subject in 'particulier/wetenschappelijk' [personal/scientific] (46 binders) and 'zaken' [business] (11 binders).
Each binder comprised a period of roughly 8 to 14 months and within it the letters were arranged alphabetically under the name of the correspondent. Zeeman also kept drafts of outgoing letters in these binders under the names of the addressees. However, he apparently only made a draft if, for some reason, the letter was difficult to write and he needed to collect his thoughts. An exception is formed by his letters to the Amsterdamsche Bank which were preserved in 13 letterpress copybooks (inv.nrs. 185-197).
On the other hand, Zeeman grouped documents relating to a function, an activity or a subject into case files. Sometimes these files contain only letters, often though, and especially those files concerning scientific research, they contain documents of all types.
Finally, Zeeman continued to use research notebooks in which he wrote down observations and data while conducting his experiments.
With the Zeeman papers were also found documents belonging to members of his family. It was thought worthwhile to include all documents belonging to Zeeman's parents in the inventory, as well as those belonging to his wife and his daughter Willemina, as far as they date from Zeeman's lifetime and shed some light on his personality.
In addition, the letters sent by Zeeman to H. Kamerlingh Onnes (inv.nr. 950) were found with the Zeeman papers. They were probably returned to him after Kamerlingh Onnes's death.
Furthermore, some documents belonging to the anti-relativist physicist Charles Menges (inv.nrs. 951-953) were among the Zeeman papers. Zeeman probably obtained these after Menges's death in 1928 (see correspondence with Dudok van Heel, inv.nr. 41).
Finally, some documents were found of which it was not possible to determine either how they came into Zeeman's possession or whether they have any relation to a case file (inv.nrs. 954-957).
Although the papers had not been properly cared for, and were found to be in considerable disarray at the time of their discovery, the small packing units on the binder, folder, and envelope level had, fortunately, remained largely intact.
Before processing, the Pieter Zeeman papers comprised 19 running meters.
Four meters of bank statements and other routine bookkeeping records and documents belonging to Zeeman's children were deaccessioned.