Sources for the early films I've added:

The Story of Treasure Island (1908): Run time 855 ft. [https://archive.org/stream/MPW02-1908-03#page/n69]

Ben's Kid (1909): This is probably Roscoe Arbuckle's first appearance in a movie, at least the first confirmed. The amount of available info about Ben's Kid is not overwhelming. However, an issue of Moving Picture World from 1909 [http://lantern.mediahist.org/catalog/moviwor04chal_0903] gives a thorough (very thorough) description of the entire movie. They mention a character called "Fatty Carter," hence my guesswork as to what role Arbuckle played. It is, however, just a guess, and if other information unbeknownst to me should be available, do change my edit with all speed.

The run time for Ben's Kid is also to be found in a Moving Picture World issue [http://lantern.mediahist.org/catalog/moviewor05chal0148]. It is listed at a 1000 feet, roughly equaling 11 minutes, give or take the speed projected. Plot details for Ben's Kid are taken from here [http://lantern.mediahist.org/catalog/moviwor04chal0903].

Mrs. Jones' Birthday (1909): Run time here [http://lantern.mediahist.org/catalog/moviewor05chal0330]. Same thing with the feets above. Plot details here [http://lantern.mediahist.org/catalog/moviewor05chal0386].

Making it pleasant for him (1909): Run time here [http://lantern.mediahist.org/catalog/moviewor05chal0756], plot details here [http://lantern.mediahist.org/catalog/moviewor05chal0846].

The Sanitarium (1910): Feet and tag line here [http://lantern.mediahist.org/catalog/moviwor07chal0779], plot details here [http://lantern.mediahist.org/catalog/moviwor07chal0948].

A Voice from the deep (1912): Plot details here [http://lantern.mediahist.org/catalog/movingpicturewor11newy1032], feet length here [http://lantern.mediahist.org/catalog/motography78elec0213]. Alas! Poor Yorick!: I'm unable to find the source for the feet length, alas (heh). However, it's a splitreeler according to [http://lantern.mediahist.org/catalog/movingpicturewor16movi_0304].

The run time for Passions, He Had Three (1913) derives from a page in Motography 1913 [http://lantern.mediahist.org/catalog/motography09elec0516]. For the love of Mabel (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec0056].

Rastus the game cock (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0056].

Safe in jail (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0056].

The Telltale Light (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec0056] Love and rubbish (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec0102]

A noice from the deep (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0102]

Love and courage (1913): split reel, 500 feet [http://lantern.mediahist.org/catalog/motography10elec_0102]

Professor Bean’s removal (1913): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/P/ProfessorBeansRemoval1913.html]

Almost a Rescue (1913): split reel, 500 feet [http://lantern.mediahist.org/catalog/motography10elec_0144]

The riot (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0144]. Also a different release date than IMDb.

Mabel’s new hero (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0224]

Fatty’s day off (1913): split reel, 500 feet [http://lantern.mediahist.org/catalog/motography10elec_0224]

The Gypsy Queen (1913): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/G/GypsyQueen1913.html]

When dreams come true (1913): Plot here [http://chroniclingamerica.loc.gov/lccn/sn88084272/1913-09-28/ed-1/seq-11/], 1 reel 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0304]

Mother’s Boy (1913): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/M/MothersBoy1913.html]

Two Old Tars (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0388]

A Quiet Little Wedding (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0388]

Fatty at San Diego (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0430], tagline [http://chroniclingamerica.loc.gov/lccn/sn83025316/1913-12-13/ed-1/seq-4/]

The milk we drink (1913): split reel, 500 feet, listed as ‘educational’ [http://lantern.mediahist.org/catalog/motography10elec_0430]

A small time act (1913): split reel, 500 feet, [http://lantern.mediahist.org/catalog/motography10elec_0430]

Wine (1913): 1 reel ,1000 feet [http://www.silentera.com/PSFL/data/W/Wine1913.html]

The Woman haters (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0516]

A ride for a bride (1913): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography10elec_0516]

Fatty’s flirtation (1913): split reel, 500 feet [http://www.silentera.com/PSFL/data/F/FattysFlirtation1913.html]

His sister’s kids (1913): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/H/HisSistersKids1913.html], tagline [http://chroniclingamerica.loc.gov/lccn/sn85042303/1914-01-16/ed-1/seq-5/]

Some nerve (1913): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/S/SomeNerve1913.html]

He Would a Hunting Go (1913): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/H/HeWouldAHuntingGo1913.html], plot here [http://chroniclingamerica.loc.gov/lccn/sn83025316/1914-01-25/ed-1/seq-10/]

A Misplaced Foot (1914): split reel, 500 feet [http://lantern.mediahist.org/catalog/motography12elec_1247]

The Under-Sheriff (1914): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography12elec_1247]

In the Clutches of the Gang (1914): 2 reels, 2000 feet [http://www.silentera.com/PSFL/data/I/InTheClutchesOfTheGang1914.html]

Rebecca's Wedding Day (1914): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography12elec_1247]

A Robust Romeo (1914): 1 reel, 1000 feet  [http://lantern.mediahist.org/catalog/motography12elec_1247]

Twixt Love and Fire (1914): 1 reel, 1000 feet  [http://lantern.mediahist.org/catalog/motography12elec_1247]

A Rural Demon (1914): 1 reel, 1000 feet [http://lantern.mediahist.org/catalog/motography12elec_1247]

Barnyard Flirtations (1914): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/B/BarnyardFlirtations1914.html], plot [http://lantern.mediahist.org/catalog/indistrictcourto06moti_0315]

The Chicken Chaser (1914): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/C/ChickenChaser1914.html]

A Bath House Beauty (1914): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/B/BathHouseBeauty1914.html]

Where Hazel Met the Villain (1914): 1 reel, 1000 feet [http://www.silentera.com/PSFL/data/W/WhereHazelMetTheVillai1914.html]

If better sources are available, do correct my edits!

Film speeds have been calculated at [http://www.panavision.co.nz/main/kbase/reference/calcfootage.asp and https://www.kodak.com/gb/en/motion/tools/film_calculator/default.htm]. The film type for these early films are often 35mm (as sources not listed above tells me. silentera.com for instance). The speed, however, varies quite a bit.