Letter to George F. FitzGerald from Charles Chree
Title
Letter to George F. FitzGerald from Charles Chree
Creator
Date
Publisher
Identifier
GFF 5/77
Subject
Description
A handwritten letter from Charles Chree to Prof, Fitzgerald which provides a detailed recommendation for scientific instruments needed for magnetic observations. Chree expresses a strong preference for Dover dip circles and suggests that a unifilar magnetometer is also necessary, recommending Dover as the supplier due to past issues with other manufacturers.
He lists the costs of the instruments and their verification, noting a total of £95 1s, and advises that transport to Ireland be handled personally to ensure their safety. Guidance is given to the maintenance of the equipment and the dangers of interference of railway lines to experiments are highlighted.
Chree concludes that he will wait for a response before proceeding with the final order.
4pp.
Dear Professor Fitzgerald
There is I think no doubt that Dover dip circles are the best. The ordinary supply is 2 dip needles which should suffice for you purpose. The other necessary instrument is a unifilar magnetometer - for declination and horizontal force measurements, We used to consider Elliott Bros. the best makers of these, but, though I believe the death of the workman skilled in the construction, their unifilar of some years ago were not very satisfactory, and from our recent experience I should be disposed to recommend Dover, always [favoured?] there is no special hurry. I mention this point because I know Dover to have a considerate amount of magnetic work in hand.
It is quite customary for us to order instruments, which it is understood we are to [lest?], and I am quite prepared to do so for you. Without verification - including annotation of tables - horizontal force observations at least are impactable.
The cost of the the instruments mentioned are as follows;
Dip Circle (2 needles) £26 5 s
Verification £ 1 1 s
Unifilar magnetometer £ 60
Verification £ 5 5 s
Packaging case £ 2 10 s
Total £ 95 1 s
This would not include transport in Ireland, Probably some trustworthy person had better take the instruments over as personal luggage,
A chronometer is required for the [vibration?] experiment in full [xxx?] force; [xxx?} these
I presume you already have as in dampness, all the magnets should be left in the absence leave in a dry place, and they should be carefully wiped after each observation if necessary.
I know of no precautions possible in the construction of the instruments themselves (but could consider [xxx?] make) there might be drying agent in the experimental hut.
There is I understand a railway line and electric [wiring?] on Valentia. I hope the experimental hut is no so near the {tracks?] as to render the rails a source of suspicion or that there is no wires near it. Any uncertainties of that source are troublesome the trains are I presume so few that any issues might be avoided.
as to the verification fees mentioned above I have no to modify or remit. I have known the Kew Committee do this in one or two special cases, but the Committee will not probably meet again until [October?] so that no application would be considered until then.
I shall await a reply before ordering the instruments, desiring to feel sure you have all the facts before you. Probably the unifilar manometer will not be ready for use until October.
Yours faithfully,
Charles Chree
superintendent
He lists the costs of the instruments and their verification, noting a total of £95 1s, and advises that transport to Ireland be handled personally to ensure their safety. Guidance is given to the maintenance of the equipment and the dangers of interference of railway lines to experiments are highlighted.
Chree concludes that he will wait for a response before proceeding with the final order.
4pp.
Dear Professor Fitzgerald
There is I think no doubt that Dover dip circles are the best. The ordinary supply is 2 dip needles which should suffice for you purpose. The other necessary instrument is a unifilar magnetometer - for declination and horizontal force measurements, We used to consider Elliott Bros. the best makers of these, but, though I believe the death of the workman skilled in the construction, their unifilar of some years ago were not very satisfactory, and from our recent experience I should be disposed to recommend Dover, always [favoured?] there is no special hurry. I mention this point because I know Dover to have a considerate amount of magnetic work in hand.
It is quite customary for us to order instruments, which it is understood we are to [lest?], and I am quite prepared to do so for you. Without verification - including annotation of tables - horizontal force observations at least are impactable.
The cost of the the instruments mentioned are as follows;
Dip Circle (2 needles) £26 5 s
Verification £ 1 1 s
Unifilar magnetometer £ 60
Verification £ 5 5 s
Packaging case £ 2 10 s
Total £ 95 1 s
This would not include transport in Ireland, Probably some trustworthy person had better take the instruments over as personal luggage,
A chronometer is required for the [vibration?] experiment in full [xxx?] force; [xxx?} these
I presume you already have as in dampness, all the magnets should be left in the absence leave in a dry place, and they should be carefully wiped after each observation if necessary.
I know of no precautions possible in the construction of the instruments themselves (but could consider [xxx?] make) there might be drying agent in the experimental hut.
There is I understand a railway line and electric [wiring?] on Valentia. I hope the experimental hut is no so near the {tracks?] as to render the rails a source of suspicion or that there is no wires near it. Any uncertainties of that source are troublesome the trains are I presume so few that any issues might be avoided.
as to the verification fees mentioned above I have no to modify or remit. I have known the Kew Committee do this in one or two special cases, but the Committee will not probably meet again until [October?] so that no application would be considered until then.
I shall await a reply before ordering the instruments, desiring to feel sure you have all the facts before you. Probably the unifilar manometer will not be ready for use until October.
Yours faithfully,
Charles Chree
superintendent
Source
RDS Library & Archives GFF collection of letters
Contributor
Rights
Copyright RDS Library & Archives. Publication, transmission or display is prohibited without formal written approval of the RDS Library & Archives.
Relation
RDS Science Archive
Format
Manuscript
Language
English
Type
Coverage
1870-1901
Collection
Citation
Chree, Charles, 1860-1928, “Letter to George F. FitzGerald from Charles Chree,” RDS Digital Archive, accessed July 18, 2025, https://digitalarchive.rds.ie/items/show/1990.