File:Contributions in geographical exploration (1920) (14594739759).jpg

Identifier: contributionsing00ohiouoft (find matches)
Title: Contributions in geographical exploration
Year: 1920 (1920s)
Authors: Ohio State University
Subjects:
Publisher: Columbus
Contributing Library: Robarts - University of Toronto
Digitizing Sponsor: MSN

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
which they were secured. In the first place, our thermocouples were insulated withunglazed porcelain tubes for about two feet at the end, andabove that with asbestos. Now, if the wires touched orwere short circuited at any place other than the twisted couple,the temperature recorded would be that of the junctionnearest to the registering instrument. Therefore, the asbestosinsulation which protected the wire was all right as long as theinstruments were dry, but if the steam condensed and saturatedthis covering or the two wires touched, the resulting temperaturewould be that of the condensed steam, or about 100° C. Thisoccurred frequently because the steam would condense whereit came in contact with the cold air at the side of the hole.We overcame this by bending the wires so that they did nottouch each other while in the steam. As almost every fumarolenecessitated a different bending of the wires, the asbestosinsulation and porcelain tubes were subjected to considerablewear and tear.
Text Appearing After Image:
March, 191.)) Temperatures of Ten Thoiiscuid Smokes 255 The same thing was apt to happen if the two wires wereallowed to rest on the wet ground, as the steam usually keptthe ground around the fumaroles damp. We therefore sup-ported the wires on some object, such as a s))ade or a j)ole.The porcelain tubes, too, would sometimes collect the con-densed steam and short circuit the instrument. As the twowires went through perforations in the same tube, the onlyremedy for this was to allow them to dry out again if theybecame saturated with water. This was usually accomplishedby allowing the thermocouple to remain in some hot fumarolefor a considerable length of time. As one had to thrust thewires from the cold air into the hot steam, more or less con-densation always occurred. If the fumarole was above 200^ C.the condensation would not be very great and the tubes wouldquickly dry out, but if it was just above the boiling point, somuch water would condense that we would get a temperatureof on

Note About Images