 | 1854 - 470 trang
...employed, and more recently achromatic illuminators have been constructed by most of our instrumentmakers. Some years since Mr. Gillett was led by observation...placed immediately behind the achromatic illuminating combination. An elastic diaphragm, or artificial pupil, as it might be called, was first proposed by... | |
 | 1854 - 662 trang
...employed, and more recently achromatic illuminators have been constructed by must of our instrument maker*. Some years since Mr. Gillett was led by observation...light and the object, but the angle of aperture of lite illuminating pencil, which can be effected only by a diaphragm placed immediately behind the achromatic... | |
 | Royal Institution of Great Britain - 1854 - 492 trang
...controlling not merely the quantity of light, which may be effected by a diaphragm placed any where between the source of light and the object, but the...placed immediately behind the achromatic illuminating combination. An elastic diaphragm, or artificial pupil as it might be called, was first proposed by... | |
 | Royal Institution of Great Britain - 1854 - 492 trang
...employed, and more recently achromatic illuminators have been constructed by most of our instrument-makers. Some years since Mr. Gillett was led by observation...light, which may be effected by a diaphragm placed any where between the source of light and the object, but the angle of aperture of the • illuminating... | |
 | 1854 - 626 trang
...employed, and more recently achromatic illuminators have been constructed by most of our instrument makers. Some years since Mr. Gillett was led by observation...importance of controlling not merely the quantity of tight which may be effected by a diaphragm placed anywhere between the source of light and the object,... | |
 | Jabez Hogg - 1856 - 530 trang
...; and more recently achromatic illuminators have been constructed by most of our instrument makers. Some years since, Mr. Gillett was led by observation...light which may be effected by a diaphragm placed any where between the source of light and the object, but the angle of aperture of the illuminating... | |
 | Jabez Hogg - 1858 - 644 trang
...; and more recently achromatic illuminators have been constructed by most of our instrument makers. Some years since, Mr. Gillett was led by observation...placed immediately behind the achromatic illuminating combination. Such a diaphragm is represented in fig. 42, manufactured by Mr. Ross : it consists of... | |
 | Jabez Hogg - 1861 - 650 trang
...employed; and more recently achromatic illuminators have been constructed by most of our instrument makers. Some years since, Mr. Gillett was led by observation...placed immediately behind the achromatic illuminating combination. Such a diaphragm is represented in fig. 42, manufactured by Mr. Ross: it consists of an... | |
 | Jabez Hogg - 1869 - 820 trang
...; and more recently achromatic illuminators have been constructed by most of our instrument makers. Some years since, Mr. Gillett was led by observation...angle of aperture of the illuminating pencil, which can.be effected only by a diaphragm placed immediately behind the achromatic illuminating combination.... | |
 | Jabez Hogg - 1871 - 808 trang
...recently achromatic illuminators have been constructed by most of our instrument makers. Some yeara since, Mr. Gillett was led by observation to appreciate...placed immediately behind the achromatic illuminating combination. Such a diaphragm is represented in fig. 99, manufactured by Mr. Ross : it Consists of... | |
| |
Some years since Mr. Gillett was led by observation to appreciate the importance of controlling, not merely the quantity of light, which may be effected by a diaphragm placed anywhere between the source of light and the object, but the angle of aperture... 
