ข้อมูลทรัพยากร

เนื้อหาย่อ : We felt that the usefulness of this catalogue be improved by dividing the experimental equip- ment into two sections according to its purpose and action: a "General equipment", that is equipment which is used to a varying extent in many different experi- mental arrangements, often in widely differing fields of physics. An example of this type of equipment are steel rods, measuring instruments, resistors, coils, photo-electric cells, lenses, light and heat sources, etc. This equipment is arranged within the appro- priate sections of the catalogue according to type. b) "Specialised equipment", used for the demon- siration and investigation of a specific physical phenomenon or law. Examples of this type of equip- ment are the water-wave unit, the unit construction motor, the discharge tube, the Fresnel mirror, the Millikan apparatus, etc. This equipment is arranged according to physical subjects. The general arrangement of the catalogue can easily be seen from the detailed index. In addition, headlines which summarise the contents of page will help the reader to find the required in- formation in the catalogue. The experimental facilities offered by the general equipment are supplemented and extended by the special equipment. The amount of special equip- ment required may vary widely for individual fields physics. For example, low-frequency electrical oscillations can be adequately covered by the ge- neral equipment while special equipment is indis- pensable for investigating the properties of elec- frons. We should like to point out that only the appro- priate special equipment is summarised under the key words of the headlines or in the index applying to special fields in physics, such as electro-magnet- ism, which means that not all the appropriate ex- perimental facilities are immediately apparent. To obtain a complete picture about experiments avail- able for any given subiect, please consult our literature. Literature references: without making any claims to completeness, the catalogue texts in many cases contain notes referring to the description of experiments in loose-leaf folders or books. These literature references are particularly useful for in- dicating the experimental arrangements and equip- ment required for a given experiment. As a rule, literature references have been included only for those special types of equipment where the necessary basic arrangement is indicated by the purpose of the experiment. On the other hand, in- dividual literature references have been omitted in the case of general equipment, much of which has a wide range of uses. For further information we wish to draw your attention to the literature relat- ing to individual experiments. We should like to take this opportunity of mentioning that operating instructions are included with all apparatus where this is considered necessary. The significance of the abbreviations used in the literature references will be found in the list of literature. lllustrations: as a rule, every description of any piece of equipment in the catalogue is supple- mented with an illustration. Only in the case of very few items where this did not appear necessary, for example in this case of glass balls, wire, thread, cord, etc., have the illustrations been omitted. Simi- larly, illustrations of chemicals and other expend- able items and spare parts have not, as a rule, been; included in this catalogue. In most cases groups of equipment are represented only by one illustration or a suitable selection. In general, these illustrations are drawn to a scale of 1:7.5. In a few exceptional cases a scale of 1:3 or 1:15 has been chosen and in such cases this is indicated near the illustration. Pnotographs: wherever the text contains ref- erences to a full-page photograph, the number of the opposite page is quoted together with the suffix "a".