62 
Maltwood_, on a Finde7\ 
On looking througli the microscope^ if with a quarter objec- 
tive^ the whole of one space^ or parts of two or more spaces^ 
will be in the field, and the figures that are seen in them will 
denote both the latitude and longitude of the object; these 
figures I write on the slide, and on any future occasion, 
when I want to find it, I have only to fix my lateral stop, 
place my finder on the stage, and after bringing the required 
part into the field, remove it, when I get the object I wish to 
examine at once before me. I register my objects by mark- 
ing a small square on the label on the slide; over this I 
write the latitude, and underneath the longitude. I then 
make a dot or cross in the square, or on one of the lines, as 
the case may be, to show the precise part of the square that 
has to be brought into the centre of the field. 
This method is, I think, more simple and more exact than 
using decimal figures, and I find not the slightest difficulty, 
with a little care, in not only placing the object at once in 
the field, but nearly always in the centre. 
The finder I have described 1 divided into fiftieths, be- 
cause I had understood that such a division had been sug- 
gested by the committee appointed to consider the subject. 
I have since ascertained that this suggestion had special 
reference to a scale to be read by the naked eye, and not to 
one used under the microscope. When I found this to be the 
case, I had a new scale written, divided into hundredths in- 
stead of fiftieths, as such a division has obviously so many ad- 
vantages, and can be used with the same facility as the other. 
I have placed this scale in the hands of Messrs. Smith 
and Beck, who have undertaken to get it photographed. 
This will give a finder of the ordinary size of the glass 
slides, three inches by one, with the centre inch divided 
into ten thousand spaces, each space containing the figures 
denoting its latitude and longitude. It took so long to 
write the figures in this scale — there being no less than 
38,400 — that it has not been possible to get any of them 
finished in time for the meeting; but I have no doubt 
that a good supply of them may be got ready for use in 
the course of a few weeks, if the weather should be suffi- 
ciently clear to admit of the negatives being taken. 
