‘What was the interest in Lord Rayleigh work on cavitation?” I wondered. “Again, we are not sure. Cavitation is a general term used to describe the behavior of voids or bubbles in a liquid. Cavitation I have found is, in many cases, an undesirable occurrence. In devices such as propellers and pumps, cavitation causes a great deal of noise, damage to components, vibrations, and a loss of efficiency.” Mycroft informed. “What was the cover to interrogate these scientists on these particular lines of questioning?” I asked. Mycroft responded, “The inquiry did not blatantly begin with the final questions, but were brought up in a course of discussion disguised as purely academic speculation and experimentation, giving no spectacular nor practical underpinning.” “Well,” I concluded,” Although you provided quite a delectable meal, overall it has been a disappointing dinner. Not that we haven’t made some progress from our conversation, but we have so much more we need to fill in before we can make any definitive conclusion or final course of action.” “And by we, you of course mean your and my agents.” Mycroft pointed out the obvious, since neither he nor I would be scattering abroad to uncover the pertinent information we needed. Or, so I thought at the time. “Thank you for your efforts, Sherlock, I will insure that a compensating check for your services will be posted.” Mycroft commended me. “You can of course stay with me tonight at my home. Although I do not have a spare bedroom, my couch is quite comfortable and can accommodate you for a night. “You can return to your bee-farm in the morning and I will keep you abreast of developments that you could aid me on.” “Thank you for your confidence, “ I replied noting his limiting offer of confiding with me on the overall case, “ But I think I will call on Watson and his lovely wife who have a standing invitation for me to stay over if I come into London. They would be slightly offended if they knew I had been relegated to my brother’s couch while they do have a spare bedroom that has been previously proffered. “He will of course want to know about the incident with Mr. Rawlings, since that is what brought me into town. I will discuss the particulars most discretely and obscure various facts at this time pertaining to why I became involved and what we have learned concerning the M Agency.” “Please do keep me informed of any developments that you can pass on to me without jeopardizing the cover and well being of your sources.” Mycroft bade me a good evening with assurances that I would be kept abreast of developments since I was involved and he might call upon me again for some minor but significant help. I caught a cross-town underground train on the newer Central London Railway. As I entered the train, I observed the small size of the rolling stock compare to above ground cars. The workmanship on the tunnels seem sub-standard. The sections of tunnel apparently were not well aligned. It is rumored that the engineers had also forgotten to take into account the height of the rails above the tunnel floor and had to rework the cars. The problem was remedied by a combination of replacing the bullhead running rails with lower profile bridge rails, and shortening the springs on the rolling stock. The locomotives caused considerable problems with vibration and the ride was considerably bumpy. These were replaced back in 1903 with motor cars, with the existing coaching stock being adapted to run as trailers. The bumpiness had smoothed out, but the tunnel alignment problem cause side to side jolting as the track weaved back and forth. My mind was concerning itself with contemplation on this minor irritation because I did not have enough information to work on the real object of my attention, the M Agency and what it was up to. After departing the train station, I hailed a cab and directed it to deposit me at Watson’s residence. The clip clop of the horse and easy sway of the cab was soothing after the smelly fumes and disjointed jolting ride in the underground. “Sherlock, how nice of you to drop in” Christy Watson was welcoming me into her parlor with a friendly face, after the maid answered the door and ushered me in. “John will return shortly, he had been called over to Mrs. Richy’s to minister to her latest bout of gout. Whatever has brought you to London and will you be staying long?” “A minor case was brought to my attention this morning and I will be returning to my bee farm in the morning.” I replied. “You must of course accept our hospitality and stay the night with us,” Watson’ s voice inserted itself into our conversation from behind me. I turned to see Watson drop his bag in the hallway and place his hat on the rack. “Oh John, I didn’t hear you come in!” Christy broke into a smile and ran passed me to hug her husband. He gave her a quick kiss and extended his hand to me.