Hello Frank:
The answer is usually due to the over use of poor quality candles (even expensive candles may be poor quality candles).
The trails are soot particles and they selectively “plate-out” on surfaces due to a process known as “thermophoresis” which is a complex mechanism that includes capacitance and temperature differentials.
By the way, that is ME in the photos on Home Energy Magazine and I’m still a little miffed about Vigil using one of my reports as the basis of his article (and the changes he made were technically incorrect to boot!) When he was watching me perform that investigation that is feature in his article, he should have at least checked with me to verify a few facts – and he should had at least informed me he was publishing the article.
Cheers,
Caoimhín P. Connell
Forensic Industrial Hygienist
Forensic Industrial Hygiene
<SMALL> (The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)
AMDG </SMALL>
